Depression appears characterised by a homogenously pro-inflammatory state: Patients show increases in pro-inflammatory immune markers mean levels, and reductions in anti-inflammatory IL-4

Inflammatory Markers in Depression: a Meta-Analysis of Mean Differences and Variability in 5,166 Patients and 5,083 Controls. Emanuele F. Osimo et al. Brain, Behavior, and Immunity, February 27 2020. https://doi.org/10.1016/j.bbi.2020.02.010

Highlights
• Patients with depression show reduced variability in pro-inflammatory immune measures.
• Patients with depression show increases in pro-inflammatory immune markers mean levels, and reductions in anti-inflammatory IL-4.
• Depression appears characterised by a homogenously pro-inflammatory state.

Abstract
Importance: The magnitude and variability of cytokine alterations in depression are not clear.

Objective: To perform an up to date meta-analysis of mean differences of immune markers in depression, and to quantify and test for evidence of heterogeneity in immune markers in depression by conducting a meta-analysis of variability to ascertain whether only a sub-group of patients with depression show evidence of inflammation.

Data Sources: Studies that reported immune marker levels in peripheral blood in patients with depression and matched healthy controls in the MEDLINE database from inception to August 29th 2018 were examined.

Study Selection: Case-control studies that reported immune marker levels in peripheral blood in patients with depression and healthy controls were selected.

Data Extraction and Synthesis: Means and variances (SDs) were extracted for each measure to calculate effect sizes, which were combined using multivariate meta-analysis.

Main Outcomes and Measures: Hedges g was used to quantify mean differences. Relative variability of immune marker measurements in patients compared with control groups as indexed by the coefficient of variation ratio (CVR).

Results: A total of 107 studies that reported measurements from 5,166 patients with depression and 5,083 controls were included in the analyses. Levels of CRP (g=0.71; 95%CI: 0.50-0.92; p<0.0001); IL-3 (g=0.60; 95%CI: 0.31-0.89; p<0.0001); IL-6 (g=0.61; 95%CI: 0.39-0.82; p<0.0001); IL-12 (g=1.18; 95%CI: 0.74-1.62; p<0.0001); IL-18 (g=1.97; 95%CI: 1.00-2.95; p<0.0001); sIL-2R (g=0.71; 95%CI: 0.44-0.98; p<0.0001); and TNFα (g=0.54; 95%CI: 0.32-0.76; p<0.0001) were significantly higher in patients with depression. These findings were robust to a range of potential confounds and moderators. Mean-scaled variability, measured as CVR, was significantly lower in patients with depression for CRP (CVR=0.85; 95%CI: 0.75-0.98; p=0.02); IL-12 (CVR=0.61; 95%CI: 0.46-0.80; p<0.01); and sIL-2R (CVR=0.85; 95%CI: 0.73-0.99; p=0.04), while it was unchanged for IL-3, IL-6, IL-18, and TNF α.

Conclusions and Relevance: Acute depression is confirmed as a pro-inflammatory state. Some of the inflammatory markers elevated in depression, including CRP and IL-12, show reduced variability in patients with depression, therefore supporting greater homogeneity in terms of an inflammatory phenotype in depression. Some inflammatory marker elevations in depression do not appear due to an inflamed sub-group, but rather to a right shift of the immune marker distribution.

Keywords: DepressionInflammationMeta-analysisHeterogeneityCytokineCRP

4. Discussion

Our meta-analysis finds evidence that mean-scaled variability, measured as CVR, is reduced in patients with depression for CRP, IL-12 and sIL-2R, while it is unchanged for IL-3, IL-6, IL-18 and TNF α. In the same sample, we also find that blood levels of CRP, IL-3, IL-6, IL-12, IL-18, sIL-2R and TNF α are significantly elevated in patients with depression with medium-large effect sizes (range 0.54-1.97), and that these findings are robust to a range of potential confounds and moderators. See Table 1 for a summary of our findings.

Our study is, to our knowledge, the first meta-analysis of variability of immune parameters in individuals with depression compared to matched controls. Mean differences in inflammatory markers in depression have been meta-analysed before (Howren et al., 2009, Dowlati et al., 2010, Haapakoski et al., 2015, Goldsmith et al., 2016, Köhler et al., 2017). However, as shown in Supplementary Table 1, this study is by far the largest meta-analysis of immune markers in depression, including a sample 1.48 times larger than the largest previous one. In addition to this, this is one of the first studies to systematically consider the effect on immune markers of excluding patients not experiencing an active depressive episode (previously only considered in a much smaller study by Goldsmith et al), duration of illness (previously only considered descriptively), study quality (previously only considered in a smaller study by Haapakoski et al), and smoking (previously only considered by Kohler et al). Furthermore, our findings of increased mean levels of CRP, IL-6, IL-12 and TNF α in depression replicate previous meta-analytical findings; the same can be said of no changes in levels of TGF β (Table 2). Reductions in IL-4, found in our study with an effect size of -0.73 and resistant to most sensitivity analyses, were not significant in Kohler et al, 2017 nor in (Dowlati et al., 2010), however both these studies were based on considerably smaller samples, which could explain the difference. More controversial is the result for IFNγ, which we find not significantly altered in our main analysis and increased in patients when excluding studies not matched for smoking levels between cases and controls. Given that previous, smaller meta-analyses were also non-concordant with regards to IFNγ (Dowlati et al., 2010, Goldsmith et al., 2016, Köhler et al., 2017), we believe therefore that more research is needed to establish the relationship between IFNγ levels and depression.

4.1. Interpretations and Implications

4.1.1. Meta-analysis of Heterogeneity

In a previous study we have shown that patients with depression show a proportion of high CRP levels at different cut-offs (CRP >1mg/L, >3mg/L and >10mg/L) that is similar to matched controls (Osimo et al., 2019); this supported the hypothesis that the shape of the CRP distribution curve is similar in patients and controls. In this study we find that mean-scaled variability of CRP and of a number of other immune markers is either reduced or unchanged in patients with depression as compared to healthy controls. A reduced variability implies a narrower distribution in patients than in controls, and possibly even a greater homogeneity in the inflammatory phenotype in depression. Therefore, the findings to date, at least for markers that show elevations of the mean and reductions in heterogeneity such as CRP, support a narrower distribution that is shifted to the right in depression. This is important as in the past there have been suggestions that inflammation in depression could be due to a sub-group of “inflamed and depressed” subjects, who might potentially be part of a separate sub-group of the depressed population (Miller and Cole, 2012). Our findings, instead, point in the direction of a continuous distribution of inflammatory markers in the depressed population, which is more homogenous than the healthy population.

The reduction in variability in CRP is worthy of a special mention here, as CRP is the main inflammatory marker routinely measured in clinical practice (Yeh, 2004;109(21_suppl_1):), and it is commonly used to stratify patients based on peripheral inflammatory levels in immunopsychiatric studies. Activation of the inflammatory system is thought to underlie antidepressant resistance (Chamberlain et al., 2018, Benedetti et al., 2002, Lanquillon et al., 2000, Carvalho et al., 2013), highlighting a potential involvement in treatment response (Carvalho et al., 2013, Maes et al., 1997, O’Brien et al., 2007, Yoshimura et al., 2009). Therefore, whether targeting inflammatory cytokines could provide therapeutic benefit for patients with depression is a key question that is being investigated in ongoing trials (e.g. NCT02473289; ISRCTN16942542). Our findings will be relevant for future studies assessing inflammation in depression, especially those recruiting patients based on their baseline inflammatory status.

4.1.2. Meta-analysis of mean differences

We found increases in the average levels of type I and other pro-inflammatory cytokines such as IL-3, IL-6, IL-12, IL-18 and TNF α; we also found reductions in IL-4, one of the main anti-inflammatory and immune-modulatory cytokines; finally, we found mean increases in CRP, which is one of the best characterised inflammatory markers in medical (Danesh et al., 2000, Visser et al., 1999) and psychiatry conditions (Fernandes et al., 2016, von Känel et al., 2007, Fernandes et al., 2016). Taken together, these results confirm that acute depression is associated with a pro-inflammatory state.

CRP is one of the best studied inflammatory markers in the field of medicine. Higher levels of CRP have been consistently found in cross-sectional studies and in population-based longitudinal studies of depression, often preceding the onset of illness (Gimeno et al., 2009, Khandaker et al., 2014, Wium-Andersen et al., 2013, Zalli et al., 2016), suggesting that inflammation could be a cause rather than simply a consequence of the illness; supporting this hypothesis, recently Mendelian randomization analyses of the UK Biobank sample found that IL-6 and CRP are likely to be causally linked with depression (Khandaker et al., 2019). Furthermore, elevated peripheral CRP levels have been found to correlate with its level in the central nervous system, with a strong correlation between plasma and CSF CRP (r = 0.855, p < 0.001) (Felger et al., 2018).

TNF α is one of the major pro-inflammatory cytokines; it is produced by dendritic cells and macrophages and is a major activator of downstream inflammatory cascades with multiple effectors (Abbas et al., 2014). During acute infection dendritic cells and macrophages also produce IL-6 and IL-12; both are type I cytokine family members, secreted in response to an acute inflammatory stimulus (Abbas et al., 2014). IL-12 plays a central role in responses to active infection promoting Th1 responses and, hence, cell-mediated immunity (Stern et al., 1996). TNF α, IL-6 and IL-12 increases in current depressive episodes underline the systemic nature of the inflammatory status, showing some similarity to the immune reaction to an active infection.

For markers found to be overall not different between patients and controls, but with variable results in sensitivity analyses (IL-5, IFNγ and TGF β), our results encourage further research, aiming to disentangle their potential tole in mediating effects of treatment (IL-5), smoking (IFNγ) or BMI differences (TGF β).

Finally, IL-2 and IL-8 were found to be increased in patients in our main analysis, but produced discordant results in sensitivity analyses due to the effect of BMI-matching; future studies should carefully match participants for BMI as this appears to be a particularly relevant factor affecting immune status.

4.2. Strengths and Limitations

The main strength of this work is the use of the largest sample of studies of inflammatory markers in depression to date; the same large sample was used to study heterogeneity and mean differences in patients as compared to controls. Even if we could not make inferences on the shape of the distribution, such as modality, as this would require individual subject data, we were able to obtain the first measure to date of the variability of inflammatory markers in depression.

A further strength of this paper is the employment of a systematic approach to the analysis of potential confounds. Given the large number of studies that focussed on inflammatory markers in depression, we were able to investigate the effect of potential psychiatric (e.g. treatment status, current depressive episode at time of sampling and duration of illness) and lifestyle confounds (e.g. age, BMI and smoking status), as well as statistical and sampling confounds (e.g. data skew and study quality). Sensitivity analyses focussing on studies with strict environmental and physiological matching provided us with greater confidence that depression is associated with the elevation of some immune parameters. Use of a multivariate meta-analytic approach to reduce the influence of multiplicity is a further strength.

Among our limitations, we included cross-sectional studies which used different tools to diagnose depression, even if only studies using ICD or DSM diagnostic criteria were included. Inconsistency between studies was moderate to high. This could reflect methodological factors, e.g. differences in assay sensitivity. However, the random-effects model used is robust to inconsistency, and would not explain our variability findings, because these reflect within-study variation (with methodologic factors common to patient and control groups in any given study). Due to data unavailability, some sensitivity analyses might be subject to type II error, i.e. false negatives; for example, BMI-matched sensitivity analyses often included samples much smaller than that of the main analysis. Furthermore, sensitivity analyses of antidepressant naïve and treatment resistant patients were not possible owing to insufficient studies.

Although all studies included in analyses used well validated quantification techniques, insufficient assay sensitivity may have limited the ability to detect subtle differences in immune parameters between patients and controls, particularly for titres beneath the limit of assay detection. Unfortunately, very few studies (2 out of 106) reported the number of samples below the limit of assay detection, so this factor could not be taken into account. Positive data skew can inflate standard deviation due to outliers within the ‘tail’ of the data (Fayers, 2011). However, we demonstrated no significant difference in the proportion of skewed data sets between patients and controls, suggesting that influence of skew was equal. Thus, excessive skew in healthy controls compared with patients was not likely contributing to results.

We excluded papers that only included patients and controls presenting the same co-morbidity or physiological state in addition to depression (such as studies in autoimmune disorders or pregnancy) to reduce the risk of bias. Most included studies excluded participants with co-morbid medical conditions, and the presence of co-morbidity in participants was assessed as one of the items of our quality assessment of papers. It was not possible to exclude all co-morbidity due to original data quality, but we are confident this issue is not going to significantly affect results as a) we used random effect models to account for additional variation; b) co-morbidity is likely to be equally distributed between cases and controls; and c) our large sample (the largest to date) allows for more individual variation without affecting results.

A very limited number of studies on CRP excluded participants presenting with an acute infection (CRP >10 mg/L); we decided to include these studies because we previously found that the odds ratio of inflammation in patients vs controls is very similar if considering all patients (OR=1.46) or excluding patients and controls with CRP >10 mg/L (OR=1.44) (Osimo et al., 2019), thus suggesting that an equal proportion of patients and controls present with acute inflammation.

4.3. Conclusions and future directions

In this study we found a reduction in mean-scaled variability in CRP, IL-12 and sIL-2R. We found increases in the mean levels of CRP, IL-3, IL-6, IL-12, IL-18, sIL-2R and TNF α in patients with depression. These results survived sensitivity analyses for psychiatric and lifestyle predictors, influence of skew, influence of poor-quality studies and publication bias.

Our results confirm that acute depression is a pro-inflammatory state, and lend support to the hypothesis that inflammatory marker elevations in depression are not due to an inflamed sub-group, but rather to a right shift of the immune marker distribution. However, future research should specifically address the inflammatory sub-group hypothesis of depression, which can only be directly tested in an individual-patient meta-analysis.

Compared to resumes that list no study abroad experience, resumes that list study abroad experience are 20-35pct less likely to receive any callback or callback for interviews

Cheng, Albert and Florick, Laura, The Value of Study Abroad Experience in the Labor Market: Findings from a Resume Audit Experiment (February 7, 2020). EDRE Working Paper No. 2020-02. http://dx.doi.org/10.2139/ssrn.3538269

Abstract: Conventional wisdom and some empirical research suggests that study abroad programs enhance skills and personal growth in ways that translate into success in the labor market. However, this research is limited by its inability to address sources of selection bias that may confound the positive relationship between study abroad experience and labor-market success. We conduct a field experiment to overcome these limitations. Using a resume audit, we estimate the causal relationship between participation in study abroad experience and the likelihood of receiving a callback from a potential employer. We also tested for potential heterogeneities by the location (i.e., Asia versus Europe) and length (i.e., two weeks versus one year) of the study abroad experience. Compared to resumes that list no study abroad experience, resumes that list study abroad experience in Asia regardless of length are about 20 percent more likely to receive a callback for an interview if the resume studied. The differences in rates increases to 25 percent when comparing resumes without study abroad experience to those that list two-week programs in Asia. Resumes that list study abroad experience in Europe for one year are 20 percent less likely to receive any callback and 35 percent less likely to receiving a call back for an interview, relative to resumes that do not list study abroad experience. Implications about the value of study abroad are discussed.

Keywords: Study abroad, Employment, Resume Audit

Bright mind, moral mind? Intelligence is unrelated to consequentialist moral judgment in sacrificial moral dilemmas

Bright mind, moral mind? Intelligence is unrelated to consequentialist moral judgment in sacrificial moral dilemmas. D. H. Bostyn, J. De Keersmaecker, J. Van Assche & A. Roets. Psychonomic Bulletin & Review, Jan 2 2020. https://link.springer.com/article/10.3758/s13423-019-01676-9

Abstract: The dual-process model of moral cognition suggests that outcome-focused, consequentialist moral judgment in sacrificial moral dilemmas is driven by a deliberative, reasoned, cognitive process. Although many studies have demonstrated a positive association of consequentialist judgment with measures of cognitive engagement, no work has investigated whether cognitive ability itself is also related to consequentialist judgment. Therefore, we conducted three studies to investigate whether participants’ preference for consequentialist moral judgment is related to their intelligence. A meta-analytic integration of these three studies (with a total N = 675) uncovered no association between the two measures (r = – .02). Furthermore, a Bayesian reanalysis of the same data provided substantial evidence in favor of a null effect (BFH0 = 7.2). As such, the present studies show that if consequentialist judgments depend on deliberative reasoning, this association is not driven by cognitive ability, but by cognitive motivation.

Cultural items that use more second-person pronouns are liked & purchased more: Rather than addressing the audience, communicating norms, or encouraging perspective taking, second-person pronouns help us think of someone in our lives

Thinking of You: How Second-Person Pronouns Shape Cultural Success. Grant Packard, Jonah Berger. Psychological Science, February 26, 2020. https://doi.org/10.1177/0956797620902380

Abstract: Why do some cultural items succeed and others fail? Some scholars have argued that one function of the narrative arts is to facilitate feelings of social connection. If this is true, cultural items that activate personal connections should be more successful. The present research tested this possibility in the context of second-person pronouns. We argue that rather than directly addressing the audience, communicating norms, or encouraging perspective taking, second-person pronouns can encourage audiences to think of someone in their own lives. Textual analysis of songs ranked in the Billboard charts (N = 4,200), as well as controlled experiments (total N = 2,921), support this possibility, demonstrating that cultural items that use more second-person pronouns are liked and purchased more. These findings demonstrate a novel way in which second-person pronouns make meaning, how pronouns’ situated use (object case vs. subject case) may shape this meaning, and how psychological factors shape the success of narrative arts.

Keywords: language, pronouns, psychological foundations of culture, arts and entertainment, open data, open materials, preregistered

The neural bases of visual mental imagery are the object of intense debate; in patients with acquired brain damage, the consensus model predicts a systematic co-occurrence of perceptual and imaginal deficits; however...

Visual mental imagery engages the left fusiform gyrus, but not the early visual cortex: A meta-analysis of neuroimaging evidence. Alfredo Spagna, Dounia Hajhajate, Jianghao Liu, Paolo Bartolomeo. bioRxiv, Feb 7 2020. https://doi.org/10.1101/2020.02.06.937151

Abstract: The neural bases of visual mental imagery (VMI) are the object of intense debate. Their identification is central to define the brain substrates our conscious experience, and can be clinically important to reveal consciousness in non-communicating patients. The dominant model of VMI stipulates a functional and anatomical equivalence between visual mental imagery and visual perception. In patients with acquired brain damage, the model predicts a systematic co-occurrence of perceptual and imaginal deficits. However, patients with lesions restricted to the occipital cortex often experience vivid mental images, even in case of cortical blindness resulting from bilateral V1 damage. Instead, patients with extensive left temporal damage are more likely to have impaired VMI. On the other hand, some neuroimaging and neuromodulatory evidence does suggest an implication of striate cortex in VMI. To address this discrepancy, we conducted an activation-likelihood-estimation-based large-scale meta-analysis of 52 functional magnetic resonance imaging experiments to map the extent of cortical activation associated with three contrasts: (1) all studies combined; (2) VMI versus Control, (3) VMI versus Perception, and (4) Motor Mental Imagery versus Control. Results from the VMI versus Control contrast demonstrated an association between VMI and activation increase in the frontoparietal and cingulo-opercular networks bilaterally, as well as of the left fusiform gyrus. Results from the VMI versus Perception contrast showed the association between VMI and activation increase of areas lateralized to the left hemisphere, including the superior and inferior frontal gyri, as well as the fusiform gyrus. Conjunction analyses between the VMI versus Control and the VMI Mental Imagery versus Perception contrasts showed the activation of the left anterior insular cortex. Results from the Motor Mental Imagery versus Control contrast showed that mental motor imagery increases the activation of the cerebellum bilaterally, of the precentral gyrus bilaterally, of the left supplementary motor area, and of the left fusiform sulcus. Conjunction analyses between the VMI versus Control and the Motor Mental Imagery versus Control contrasts showed the activation of the right superior frontal gyrus. Thus, the results stress the importance for VMI of brain networks associated with attentional control and working memory functions, together with rostral portions of the cortical ventral visual stream. Bayesian analysis confirmed the lack of evidence for an activation of the early visual areas in VMI, consistent with the evidence from brain-damaged patients. Our evidence suggests a revision of the VMI model. A Fusiform Imagery Node in the area FG3 of the left fusiform gyrus might act as a hub retrieving visual information from long-term semantic memory in the anterior temporal lobe, in connection with the medial temporal lobe, important for a vivid VMI episodic experience. Fronto-parietal networks subserving attention and working memory initiate, modulate and maintain activity of the core VMI network in the left temporal lobe. The revised model of VMI reconciles findings from neuroimaging with the reports of patients with brain damage.

We conclude that antitrust restrictions seeking to limit intra-industry common ownership are not currently warranted

Koch, Andrew and Panayides, Marios A. and Thomas, Shawn, Common Ownership and Competition in Product Markets (February 6, 2020). 29th Annual Conference on Financial Economics & Accounting 2018; Journal of Financial Economics (JFE): http://dx.doi.org/10.2139/ssrn.2965058

Abstract: We investigate the relation between common institutional ownership of the firms in an industry and product market competition. We find that common ownership is neither robustly positively related with industry profitability or output prices nor robustly negatively related with measures of non-price competition, as would be expected if common ownership reduces competition. This conclusion holds regardless of industry classification choice, common ownership measure, profitability measure, non-price competition proxy, or model specification. Our point estimates are close to zero with tight bounds, rejecting even modestly-sized economic effects. We conclude that antitrust restrictions seeking to limit intra-industry common ownership are not currently warranted.

Keywords: Common Ownership, Governance, Competition, Horizontal Merger
JEL Classification: G34, L13, L41

Not as cold as a fish... Relationships between the Dark Triad personality traits and affective experience during the day

As cold as a fish? Relationships between the Dark Triad personality traits and affective experience during the day: A day reconstruction study. Irena Pilch. PLOS, February 25, 2020. https://doi.org/10.1371/journal.pone.0229625

Abstract: The Dark Triad of personality is a cluster of three socially aversive personality traits: Machiavellianism, narcissism and psychopathy. These traits are associated with a selfish, aggressive and exploitative interpersonal strategy. The objective of the current study was to establish relationships between the Dark Triad traits (and their dimensions) and momentary affect. Machiavellianism, grandiose narcissism, vulnerable narcissism and the dimensions of the Triarchic model of psychopathy (namely, boldness, meanness and disinhibition) were examined. We used the Day Reconstruction Method, which is based on reconstructing affective states experienced during the previous day. The final sample consisted of 270 university students providing affective ratings of 3047 diary episodes. Analyses using multilevel modelling showed that only boldness had a positive association with positive affective states and affect balance, and a negative association with negative affective states. Grandiose narcissism and its sub-dimensions had no relationship with momentary affect. The other dark traits were related to negative momentary affect and/or inversely related to positive momentary affect and affect balance. As a whole, our results empirically demonstrated distinctiveness of the Dark Triad traits in their relationship to everyday affective states. These findings are not congruent with the notion that people with the Dark Triad traits, who have a dispositional tendency to manipulate and exploit others, are generally cold and invulnerable to negative feelings. The associations between the Dark Triad and momentary affect were discussed in the contexts of evolutionary and positive psychology, in relation to the role and adaptive value of positive and negative emotions experienced by individuals higher in Machiavellianism, narcissism and psychopathy.

Discussion

The aim of the present study was to examine relationships between affective states in everyday life and dark personality traits. The associations between momentary affect and the Dark Triad were investigated using the DRM, a well-validated instrument for the measurement of daily life experience. This method enables assessing affective states within natural situations during a chosen day of one’s life. In the current study, it was assumed that narcissism and psychopathy were multidimensional constructs. The results provide evidence about the relationships of the Dark Triad with momentary affect, supporting the majority of the predictions.
According to the results, dark traits or their dimensions showed specific associations with momentary affect: momentary PA was positively related to boldness and negatively related to vulnerable narcissism, meanness and Machiavellianism; momentary NA was positively related to vulnerable narcissism, disinhibition and Machiavellianism, and also inversely related to boldness. Affect balance showed associations with boldness (positive) and with vulnerable narcissism, Machiavellianism, disinhibition and meanness (negative). These and other results of the present study are discussed below separately for Machiavellianism, narcissism and psychopathy using evolutionary theory and adaptationist approach to emotions.

Machiavellianism

When formulating the hypothesis on the association of Machiavellianism with momentary affect, we pointed out the inconsistency between the “cool syndrome” (traditionally considered a main feature of high Machs’ emotionality; [50]) and the results of many studies that revealed the positive correlations of Machiavellianism with neuroticism [e.g., 52]. In the current study, we obtained the predicted positive associations between Machiavellianism and momentary NA, and the negative associations of Machiavellianism with momentary PA and affect balance. These results did not support the conviction about “cold” and “smart” Machiavellians who can control successfully their emotions and “get what they want” form other people (see [50]).
In fact, in the description of the Machiavellian personality made in a classic work by Christie and Geis [50], there seems to be a discrepancy between the above features of high Machs and their very pessimistic view of the world where people are susceptible to manipulation, but they are also cunning and constantly lurking for someone’s mistake or a moment of inattention to achieve their goals at his or her expense. Such a worldview may create constant pressure on Machiavellians who (in their opinion) have to continuously defend themselves against other people. Because the Mach IV scale (in which at least 1/3 of items concerns views on people in general, e.g., “Most people are basically good and kind,” inversely scored) is still used as a measure of Machiavellianism, these negative beliefs are crucial to the assessment although the descriptions of the construct sometimes emphasize only manipulation, not views. On the other hand, one should not be surprised that the inhabitants of the Machiavellian, “dog-eat-dog” world tended to feel more negative and less positive emotions in everyday life, which appeared in our study. According to an evolutionary approach to emotions, “negative emotions motivate the organism to avoid misfortune by escaping, attacking, or preventing harm or by repairing damage” [124] (p. 132), so these emotions seem useful for Machiavellians, constantly surrounded by “enemies.” At the same time, such a tendency may be characterized as lower emotional well-being, which is in line with the results of many studies [e.g., 19,20].
Several current studies have provided arguments supporting the assumption about some kind of emotional vulnerability of people higher in Machiavellianism. In a study by Szijjarto & Bereczkei [39], Machiavellianism was connected with difficulties to express and understand one’s own emotions, but also with emotional instability and ability to experience strong emotions. Inability to express feelings can favor a manipulator. It is due to the fact that it is more difficult for others to catch them. However, it may also cause some costs for a Machiavellian. For instance, this inability can be an obstacle to communication in different situations (not only in close relationships). The recent study [125] has demonstrated the unexpected results, contradictory to the idea of “cold” Machiavellians: Machiavellianism positively predicted break-up distress in romantic relationships. Findings of some other studies may be reinterpreted when the assumed Machiavellian “vulnerability” is taken into account. For example, high Machs tended to engage in cheating only when the risk of being caught is small [126], which can be an effect of high levels of negative emotions experienced. The relationship between Machiavellianism and anxiety sensitivity to social concerns (concern of being rejected by others; [127]) may be partly a result of a Machiavellian view of social life and fear of retaliation. Jonason et al. [17] hypothesized that long-term strategizing (e.g., a delay of gratifications) may be an additional source of stress for Machiavellians, which can be associated with poor health outcomes. The negative relationship between Machiavellianism and various psychological and physical health indicators [17,128,129] is also in line with our hypothesis of Machiavellian vulnerability. In general, negative emotions (conceptualized as defensive mechanisms) can protect Machiavellian individuals from danger and increase their individual fitness. At the same time, this may generate considerable costs for persons higher in Machiavellianism in terms of health and emotional well-being.

Narcissism

Grandiose narcissism is connected with traits that can promote experiencing positive emotions, such as high self-esteem, extraversion and low neuroticism [46]. However, in our study this dimension of narcissism showed no relationships with momentary affect. Also none of the facets of grandiose narcissism was a significant predictor of affect.
In the present study participants were asked to state whether they were alone or with others in a given situation. Starting from the assumption that being with other people, who can give attention, respect, or admiration, may be more rewarding for the participants with higher grandiose narcissism than for those with lower grandiose narcissism (see [123]), we tested the prediction that grandiose narcissism may serve as a moderator of the association between positive affect and the type of social situation (alone vs. with others). The results provided some support for this prediction: Grandiose Exhibitionism, which is good indicator of narcissistic grandiosity [112], was responsible for this moderation.
The specificity of grandiose narcissism is that narcissistic individuals prefer other people’s company because they constantly seek attention and admiration of others in order to maintain their grandiose self-views [130]. Grandiose narcissists can benefit from experiencing positive affective states in the presence of others because it can help them to avoid catching signals of criticism, a lack of acceptance, or other potential sources of ego threats and enhance the effectiveness of self-presentation (see [131]). Positive affect may help narcissists maintain positive illusions about their own attractiveness, which “may compel narcissists to indiscriminately pursue short-term mating strategy beyond their realistic prospects” [132] (p. 213). Positive emotions shared by individuals build friendship, alliances and family bonds [133]. Moreover, persons who express more positive emotions are rated more positively and people generally prefer interacting with those who have a good mood [134]. Thus, it seems that a tendency to feel more positive emotions while with others can be adaptive for individuals higher in narcissism and increase the effectiveness of the narcissistic strategy.
There has been an unresolved discussion in psychology on whether grandiose narcissism should be treated as an adaptive or maladaptive trait. Our results do not support any conclusions regarding this issue. However, the lack of a main effect of grandiose narcissism (and its sub-dimensions) on momentary PA and momentary NA and a moderating effect of grandiose narcissism (and Grandiose Exhibitionism) on the relationship between being alone or with others and momentary PA encourage us to consider other possible contextual moderators, such as types of situation, communication or interpersonal relationships.
Vulnerable narcissism is defined by such features as neuroticism, anxiety and a tendency to feel high negative affect and low positive affect, and these relationships were replicated in many cross-sectional studies [e.g., 46]. The results of our study provided support to the idea that these tendencies are also observed in everyday life. When considered alone, vulnerable narcissism was relatively the strongest predictor of momentary NA. Additionally, unfavorable affect balance was observed. Since affect is regarded as an important component of subjective well-being, this pattern of relationships prompted the conclusion that this type of a narcissist may pay the highest personal costs related to the emotional aspect of well-being out of all dark personalities due to the emotional vulnerability. On the other hand, narcissistic behavioral strategy is based on exploitation of others; however, vulnerable narcissism is associated with experiencing difficulties in establishing and maintaining interpersonal relationships [135]. Thus, some of these negative emotional states can result in inhibiting the unrealistic aspirations and demands in the name of security (e.g., to prevent the loss of a partner), which can be viewed as adaptive.

Psychopathy

The triarchic model of psychopathy [73], which was adopted in the current study, proposes boldness (“fearless dominance”,) defined as more “positive” phenotypic expression of fearless temperament, as a dimension of psychopathy. According to the findings of the present study, boldness was the only component of psychopathy (and the only dark trait) that turned out to be positively related to momentary PA and affect balance and negatively related to momentary NA. In other words, only boldness exhibited a pattern of relationships with momentary affect that can be considered psychologically beneficial for a “bold” individual, and that can also be interpreted in terms of higher subjective well-being. The possible biologically adaptive value of positive emotions is also important. Positive emotional states communicate that an individual is safe, healthy, full of energy, so he or she is able to take more risks and make good use of to gain valuable resources. This finding is consistent with earlier studies that demonstrated similar relationships between boldness and a trait positive/negative affect, resiliency [92,89], and well-being [90]. Although boldness is also considered to be connected with diminished physiological and emotional responsiveness [91], our study did not confirm this in relation to positive affective states.
According to our results, disinhibition was associated with momentary NA and negatively with affect balance, so it predicted more negative affective states and unfavorable affect balance. However, momentary PA was not related to disinhibition. The relationship between disinhibition and momentary NA was relatively strong and remained significant after controlling for all the Dark Triad traits. Disinhibition embodies this type of psychopathy that is not related to blunted emotional reactivity [91] but is associated with poor emotional control and irresponsible and impulsive behavior [e.g., 136]. This can lead to situations resulting in distress and negative feelings. However, even persistent negative emotional states can be understood as “an adaptive response to unfavorable circumstances” ([137] p. 100). Thus, taking into account evolutionary functions of emotions, these negative emotional states experienced by disinhibited individuals could prevent them from too risky behavior, which can be beneficial for them (i.e., improve their fitness).
Contrary to the predictions, meanness was not associated with momentary NA. The prediction about negative association between meanness and momentary NA was made based on the characteristics of meanness as callous-unemotional aspect of psychopathy and taking into account the results of previous studies on relationships between this dimension and trait negative affectivity. Meanness as a “callous-unemotional” dimension of psychopathy was connected with deficits in experiencing fear and some other negative emotions [e.g., 138]. However, the findings of other studies on triarchic psychopathy showed different patterns of correlations between meanness and some characteristics associated with negative affectivity. For example, in a study by Brislin et al. [139] no relationship was obtained between trait negative affect and meanness in an incarcerated group, and in a community group this relationship was positive. In a recent meta-analysis [89], despite the fact that triarchic meanness was strongly associated with other models of psychopathy and relevant criteria, it was also positively related to neuroticism, Negative Affectivity as measured by the Personality Inventory for the DSM-5, and internalizing symptoms (anxiety and depression). Additionally, the findings regarding internalizing symptoms turned out highly overlapping for meanness and disinhibition [89]. These meta-analytic findings allow believing that the lack of negative associations between meanness and momentary NA in the current study may be partly the effect of the specificity of measurement of the triarchic meanness. It is also possible that the levels of participants’ meanness were not large enough to demonstrate the expected effects in our group or that the indicators of momentary NA used in the current study were not optimal in the case of meanness as correlations between this psychopathy dimension and particular negative emotional states may be different (e.g., negative for fear and positive for anger).
Meanness turned out to be a negative predictor of momentary PA, which was not anticipated, and remained significant when the Dark Triad traits were considered together. Deficits in experiencing positive emotions are rather not assigned to psychopathy, but some studies showed deficient processing of positive emotional stimuli [138]. The negative relationship between meanness and PA may be also associated with the above-mentioned overlap between triarchic meanness and disinhibition. Overall, our results are in line with the idea that meanness can be connected with poverty of emotional experience, however, our evidence is weak.
A different way to interpret the differences regarding emotions is to analyze more basic personality elements that are behind the particular dark traits and their dimensions [140]. The traits which are shared by all the DT constructs constitute the so-called “dark core” [141,142] that includes Honesty-Humility, disagreeableness [8,143–145], callousness [146], and antagonism [141]. These common features, in themselves, cannot be responsible for differences in emotions. Nevertheless, both the behavior components and other traits may be specific for particular dark personalities. For example, disinhibition, vulnerable narcissism and, to a lesser degree, Machiavellianism are associated with higher neuroticism and introversion [45,52,73], which promotes experiencing negative emotions. Conversely, boldness and grandiose narcissism are related to extraversion, agency, social dominance and high self-esteem [68,73], which can promote positive emotions on different ways [147,148]. However, in the current study, it was the case only for boldness.

Conclusions and limitations

In summary, we investigated the relationships between the Dark Triad and momentary affective states utilizing an ecologically valid method. Our findings contribute to the literature by clarifying how the Dark Triad traits are related to everyday emotional experience. Different patterns of relationships of momentary PA, momentary NA and affect balance with the dark personality constructs were obtained. The two dimensions of narcissism demonstrated different relationships with daily affectivity and the same was true for the three dimensions of psychopathy and Machiavellianism. The Dark Triad traits explained together a noticeable part of momentary NA variance (21%), but their associations with PA were weaker.
On the basis of our results, only boldness was associated with positive affective states, which seems beneficial to an individual. The participants with higher levels of vulnerable narcissism, disinhibition and Machiavellianism were predisposed to more negative and less positive affect and their affect balance may be seen as unfavorable to them in a given situation. These results can be interpreted in the framework of evolutionary psychology. We speculate that the differences in momentary affect obtained in the current study reflect different behavioral strategies used in daily life by individuals. A tendency to feel negative emotions that was observed in Machiavellian and disinhibited persons and vulnerable narcissists may be conducive to achieving their goals by increasing caution and mistrust in dealing with others, which may reduce the risk of being disclosed and protect against risking too much. In turn, the positive emotions of bold individuals can make it easier to take risks when the situation is favorable whereas the positive emotions of grandiose narcissists (experienced in the presence of others) can make it easier to gain attention, acceptance or admiration.
The current study was the first that investigated everyday affective states in relation to narcissism, Machiavellianism and psychopathy simultaneously. The results confirmed the existence of different patterns of relationships between the Dark Triad traits and momentary affect. The significant overlap between the Dark Triad traits, found in numerous research studies, triggers a discussion whether there is a need of considering all these traits. It is especially important in the case of Machiavellianism and psychopathy because of the “dark dyad” hypothesis [20,149,150] that emphasizes the importance of the similarity between these constructs and their separateness from narcissism. Our results do not support this hypothesis and the idea that Machiavellianism and psychopathy measure the same construct (see [151]) because of the lack of similarity between Machiavellianism and the dimensions of triarchic psychopathy with reference to momentary affect. The relationships of Machiavellianism with momentary affect were congruent with the results for vulnerable narcissism rather than those for psychopathy dimensions. In reference to triarchic psychopathy, the current findings provided support for theory and previous research, confirming the distinctiveness of the three dimensions of psychopathy and the specificity of boldness (as a “positive” psychopathic trait) in the domain of affective functioning. Taken as a whole, the current findings seem to support the appropriateness of multidimensional approach to investigating psychopathy and narcissism as elements of the Dark Triad as a way to deal with the excessive overlap of Machiavellianism and unidimensional psychopathy.
The present study has several limitations. Firstly, it relies on data from a convenience sample of university students, which limits the generalization of the results.
Secondly, all data were obtained from self-report, which has some disadvantages. Personality constructs are commonly measured using self-report questionnaires [152]. To minimize common method biases we applied several techniques recommended by Podsakoff, MacKenzie, Lee and Podsakoff [153]. Well-established and valid questionnaires were chosen to reduce statement ambiguity. Each questionnaire was placed separately with a separate instruction. Participants’ anonymity was preserved in the data collection process, which could reduce social desirability bias. However, multi-method assessment could be valuable for future studies and self-report data should be complemented by informant ratings or behavioral observation [154]. Thirdly, to minimize participants’ burden and increase the accuracy of completing the “diary,” only a few emotional words have been used to assess momentary affect. Future studies should address this issue by using a larger and more representative set of emotional words. Moreover, a dimensional perspective on emotional experience, which was adopted in our study, is only one of the possible perspectives. From an evolutionary point of view, emotions can be understood as solutions to specific ecological problems. Therefore, it would be recommended for future studies to examine relationships between the Dark Triad traits and the particular emotional states using the categorical approach to emotions [155,156]. Fourthly, the relatively low reliability coefficients (Cronbach’s alphas) were obtained for the HSNS and NPI, which can reduce statistical power. Nevertheless, in the current study, the relationships between vulnerable narcissism (HSNS) and affect were significant and consistent with the predictions. Generally, the HSNS is regarded as a well-established and valid measure of narcissistic vulnerability. However, it cannot be excluded that lower reliability of the NPI could attenuate the relationships between the NPI and affect. Fifthly, despite the fact that the DRM was developed to reduce memory biases, it cannot be excluded that such biases could occur and influence the result of the current study [157].
To summarize, in this study relationships between the Dark Triad traits and daily emotional experience were investigated. In general, dark traits (except boldness) were not related to momentary positive affect, but most of them were associated with higher levels of momentary negative affect. In particular, persons higher in Machiavellianism, vulnerable narcissism and disinhibition share a tendency to experience more negative affect during a day. This tendency may lower their subjective well-being, but it can also be interpreted as a defense mechanism protecting them from taking (too) risky actions and decisions.

The overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero

Altruism, fast and slow? Evidence from a meta-analysis and a new experiment. Hanna Fromell, Daniele Nosenzo & Trudy Owens. Experimental Economics, February 25 2020. https://link.springer.com/article/10.1007/s10683-020-09645-z

Abstract: Can we use the lens of dual-system theories to explain altruistic behavior? In recent years this question has attracted the interest of both economists and psychologists. We contribute to this emerging literature by reporting the results of a meta-study of the literature and a new experiment. Our meta-study is based on 22 experimental studies conducted with more than 12,000 subjects. We show that the overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero. One reason for this null result could be that promoting intuition has heterogeneous effects on altruism across different subgroups of subjects or contexts. Another reason could be that there simply is no real effect and that previously reported single results are false positives. We explore the role of heterogeneity both by performing a mediator analysis of the meta-analytic effect and by conducting a new experiment designed to circumvent the issue of potential heterogeneity in the direction of the effect of promoting intuition. In both cases, we find little evidence that heterogeneity explains the absence of an overall effect of intuition on altruism. Taken together, our results offer little support for dual-system theories of altruistic behavior.

Discussion and conclusions

In this paper, our aim was to probe the validity of a dual-system approach to altruistic behavior, by testing the hypothesis that trade-offs between self-interest and altruism trigger a conflict between our “fast”, intuitive System 1 and our “slower”, more deliberative System 2. We performed a meta-analysis of the existing literature on the relation between altruism and intuition/deliberation and found that the manipulations used in previous experiments to promote the intuitive system at the expense of the deliberative system (using ego depletion tasks, cognitive load, time pressure or priming) have an overall effect on altruism that is very close to, and not significantly different from, zero.

Can this aggregate null result be due to the fact that the relation between altruism and our two systems is genuinely heterogeneous across different subgroups and decision situations, as some researchers have suggested? We find little evidence that this may be the case. We first run a mediator analysis based on the existing literature and consider a number of potential mediators of the relation between intuition and altruism (including mediators previously suggested in the literature, such as gender, the stakes of the experiment, or the frame of the task). We find that none of the mediators included in the analysis play a significant role in explaining the mixed results in existing studies. One possible exception is the frame of the task, for which we find evidence of a mediating effect in some specifications of the analysis, but not in others.

We then designed and ran a new experiment that allowed us to probe the validity of dual-system theories of altruism without being vulnerable to the presence of unobserved and/or unanticipated heterogeneity in the relation between altruism and intuition. We argue that, if trade-offs between altruism and self-interest trigger a conflict between the intuitive and deliberative systems, then being exposed to these trade-offs should be willpower-depleting. We do not find evidence that this is the case. Directionally, the effect is in line with the hypothesis: subjects who were exposed to trade-offs between altruism and self-interest perform worse on a task that requires willpower than subjects who were not exposed to such trade-offs. However, we cannot reject the null that the two groups perform similarly.Footnote 20

Overall, the combination of evidence from the meta-study and the new experiment suggests that choices that involve trade-offs between altruism and self-interest do not trigger any strong conflict between intuition and deliberation. This could be because, in the realm of altruistic behavior, the decision processes governed by the intuitive and deliberative systems may actually both lead to the same outcome for any given individual. That is, the two systems are not actually in conflict when it comes to making these type of decisions, and hence their outcome is the same. Alternatively, the null results reported in the literature and in our new experiment could mean that the lens of dual-system models does not extend to altruistic behavior. In either case, our study offers little support for the notion that, in the domain of altruistic choices, the individual must spend cognitive resources to override the intuitive impulse when the person wants to take a choice favored by the deliberative system.

Animals use many different types of traits to attract mates & outcompete rivals, including colours, songs, & horns, but it remains unclear why, for example, some taxa have songs, others colours, & others horns

Songs versus colours versus horns: what explains the diversity of sexually selected traits? John J. Wiens, E. Tuschhoff. Biological Reviews, February 24 2020. https://doi.org/10.1111/brv.12593

ABSTRACT: Papers on sexual selection often highlight the incredible diversity of sexually selected traits across animals. Yet, few studies have tried to explain why this diversity evolved. Animals use many different types of traits to attract mates and outcompete rivals, including colours, songs, and horns, but it remains unclear why, for example, some taxa have songs, others have colours, and others horns. Here, we first conduct a systematic survey of the basic diversity and distribution of different types of sexually selected signals and weapons across the animal Tree of Life. Based on this survey, we describe seven major patterns in trait diversity and distributions. We then discuss 10 unanswered questions raised by these patterns, and how they might be addressed. One major pattern is that most types of sexually selected signals and weapons are apparently absent from most animal phyla (88%), in contrast to the conventional wisdom that a diversity of sexually selected traits is present across animals. Furthermore, most trait diversity is clustered in Arthropoda and Chordata, but only within certain clades. Within these clades, many different types of traits have evolved, and many types appear to have evolved repeatedly. By contrast, other major arthropod and chordate clades appear to lack all or most trait types, and similar patterns are repeated at smaller phylogenetic scales (e.g. within insects). Although most research on sexual selection focuses on female choice, we find similar numbers of traits (among sampled species) are involved in male contests (44%) and female choice (55%). Overall, these patterns are largely unexplained and unexplored, as are many other fundamental questions about the evolution of these traits. We suggest that understanding the diversity of sexually selected traits may require a shift towards macroevolutionary studies at relatively deep timescales (e.g. tens to hundreds of millions of years ago).

Money: An Integrated Review and Synthesis From a Psychological Perspective

Money: An Integrated Review and Synthesis From a Psychological Perspective. Xijing Wang, Zhansheng Chen, Eva G. Krumhuber. Review of General Psychology, February 23, 2020. https://doi.org/10.1177/1089268020905316

Abstract: Many empirical studies have demonstrated the psychological effects of various aspects of money, including the aspiration for money, mere thoughts about money, possession of money, and placement of people in economic contexts. Although multiple aspects of money and varied methodologies have been focused on and implemented, the underlying mechanisms of the empirical findings from these seemingly isolated areas significantly overlap. In this article, we operationalize money as a broad concept and take a novel approach by providing an integrated review of the literature and identifying five major streams of mechanisms: (a) self-focused behavior; (b) inhibited other-oriented behavior; (c) favoring of a self–other distinction; (d) money’s relationship with self-esteem and self-efficacy; and (e) goal pursuit, objectification, outcome maximization, and unethicality. Moreover, we propose a unified psychological perspective for the future—money as an embodiment of social distinction—which could potentially account for past findings and generate future work.

Keywords: money, psychological effects, integrated review, unified perspective

Laws against wrongdoing may originate in intuitions that are part of universal human nature, according to the adaptationist theory, which proposes that laws can be traced to neurocognitive mechanisms and ancestral selection pressures

The origins of criminal law. Daniel Sznycer & Carlton Patrick. Nature Human Behaviour, February 24 2020. https://www.nature.com/articles/s41562-020-0827-8

Abstract: Laws against wrongdoing may originate in justice intuitions that are part of universal human nature, according to the adaptationist theory of the origins of criminal law. This theory proposes that laws can be traced to neurocognitive mechanisms and ancestral selection pressures. According to this theory, laypeople can intuitively recreate the laws of familiar and unfamiliar cultures, even when they lack the relevant explicit knowledge. Here, to evaluate this prediction, we conduct experiments with Chinese and Sumerian laws that are millennia old; stimuli that preserve in fossil-like form the legal thinking of ancient lawmakers. We show that laypeople’s justice intuitions closely match the logic and content of those archaic laws. We also show covariation across different types of justice intuitions: interpersonal devaluation of offenders, judgements of moral wrongness, mock-legislated punishments and perpetrator shame—suggesting that multiple justice intuitions may be regulated by a common social-evaluative psychology. Although alternative explanations of these findings are possible, we argue that they are consistent with the assumption that the origin of criminal law is a cognitively sophisticated human nature.

Single dose testosterone administration increases men’s facial femininity preference in a Chinese population

Single dose testosterone administration increases men’s facial femininity preference in a Chinese population. Chengyang Han et al. Psychoneuroendocrinology, February 20 2020, 104630. https://doi.org/10.1016/j.psyneuen.2020.104630

Highlights
•    Testosterone administration increases men’s facial femininity preferences.
•    Chinese men preferred femininity over masculinity in women’s faces.
•    Testosterone has a causal effect on men’s facial preferences.

Abstract: Sex hormones are thought to influence human mate preferences. Previous studies have reported mixed results regarding the association between men’s testosterone levels and their mate preferences. The present study investigated the effect of testosterone administration on men’s facial femininity preference. Heterosexual Chinese male participants (n = 140) received a single dose of 150 mg testosterone or placebo gel in a double-blind, placebo-controlled, between-participant design. Results showed that Chinese men demonstrated general preferences for feminized women’s faces, consistent with previous results from the Western population. More importantly, men showed stronger attraction to femininity in women’s faces three hours after testosterone administration than at the beginning of the session. In the placebo group, no significant change in facial femininity preferences was found between time points. These results indicate that exogenous testosterone increases men’s facial femininity preferences in a Chinese population.

Less agreeable, better preserved? Lower Agreeableness is associated with better preservation of limbic area; aging-related hippocampal volume decrease is lower in elders with higher openness

Less agreeable, better preserved? A PET amyloid and MRI study in a community-based cohort. Panteleimon Giannakopoulos et al. Neurobiology of Aging, February 19 2020. https://doi.org/10.1016/j.neurobiolaging.2020.02.004

Highlights
•    Lower Agreeableness is associated with better preservation of limbic areas
•    Aging-related hippocampal volume decrease is lower in elders with higher openness
•    Personality impact on brain volume is independent of amyloid load and APOE genotype

Abstract: The relationship between personality profiles and brain integrity in old age is still matter of debate. We examined the association between Big Five factor and facet scores and MRI brain volume changes upon a 54-month follow-up in 65 elderly controls with three neurocognitive assessments (baseline, 18 and 54 months), structural brain MRI (baseline and 54 months), brain amyloid PET during follow-up, and APOE genotyping. Personality was assessed with the Neuroticism Extraversion Openness Personality Inventory-Revised. Regression models were used to identify predictors of volume loss including time, age, sex, personality, amyloid load, presence of APOE epsilon 4 allele and cognitive evolution. Lower agreeableness factor scores (and four of its facets) were associated with lower volume loss in hippocampus, entorhinal cortex, amygdala, mesial temporal lobe and precuneus bilaterally. Higher openness factor scores (and two of its facets) were also associated with lower volume loss in left hippocampus. Our findings persisted when adjusting for confounders in multivariable models. These data suggest that the combination of low agreeableness and high openness is an independent predictor of better preservation of brain volume in areas vulnerable to neurodegeneration.

White-faced capuchin monkey dyads in Costa Rica practice idiosyncratic interaction sequences that involve an unusual intensity of focus on the partner, behaviours of no immediate utilitarian purpose that sometimes involve "sacred objects"

Capuchin monkey rituals: an interdisciplinary study of form and function. Susan Perry, Marco Smolla. bioRxiv, Feb 24 2020. https://doi.org/10.1101/2020.02.21.958223

Abstract: Many white-faced capuchin monkey dyads in Lomas Barbudal, Costa Rica, practice idiosyncratic interaction sequences that are not part of the species-typical behavioural repertoire. These interactions often include uncomfortable or risky elements. These interactions exhibit the following characteristics commonly featured in definitions of rituals in humans: (1) they involve an unusual intensity of focus on the partner, (2) the behaviours have no immediate utilitarian purpose, (3) they sometimes involve "sacred objects", (4) the distribution of these behaviours suggests that they are invented and spread via social learning, and (5) many behaviours in these rituals are repurposed from other behavioural domains (e.g. extractive foraging). However, in contrast to some definitions of ritual, capuchin rituals are not overly rigid in their form, nor do the sequences have specific opening and closing actions. In our 9,260 hours of observation, ritual performance rate was uncorrelated with amount of time dyads spent in proximity but is (modestly) associated with higher relationship quality and rate of coalition formation across dyads. Our results suggest that capuchin rituals serve a bond-testing rather than a bond-strengthening function. Ritual interactions are exclusively dyadic, and between-dyad consistency in form is low, casting doubt on the alternative hypothesis that they enhance group-wide solidarity.

Democrats overestimate the explicit prejudice of the American electorate, & thus see disadvantaged groups as less electable; Democrats who frequently interacted with Republicans had more accurate estimations of explicit prejudice

Mercier, Brett, Jared Celniker, and Azim Shariff. 2020. “Overestimating Explicit Prejudice Causes Democrats to Believe Disadvantaged Groups Are Less Electable.” PsyArXiv. February 24. doi:10.31234/osf.io/s52qz

Abstract: Three studies show that Democrats overestimate the explicit prejudice of the American electorate, and thus see disadvantaged groups as less electable. Study 1 found that Democrats underestimated the percentage of Americans who say they would vote for presidential candidates from disadvantaged groups. Study 2 replicated this finding and demonstrated that Democrats who perceive high levels of explicit prejudice towards a group also believe presidential candidates from that group would be less electable. Moreover, Democrats who frequently interacted with Republicans had more accurate estimations of explicit prejudice. Study 3 found that correcting misperceptions about explicit prejudice made Democrats believe generic presidential candidates from disadvantaged groups would be more electable. We did not find evidence that correcting misperceptions affected beliefs about the electability of specific candidates in the 2020 Democratic Primary or support for these candidates.

Ability self-estimates (SEs) exhibit strong correlations with personality traits; in most domains, personality explains more variance in SEs than abilities do

Self-estimates of abilities are a better reflection of individuals’ personality traits than of their abilities and are also strong predictors of professional interests. Aljoscha C. Neubauer, Gabriela Hofer. Personality and Individual Differences, February 24 2020, 109850. https://doi.org/10.1016/j.paid.2020.109850

Highlights
• Ability self-estimates (SEs) exhibit strong correlations with personality traits.
• Personality predicts SEs independently of measured abilities and grades.
• In most domains, personality explains more variance in SEs than abilities do.
• Interests are mostly a function of self-estimated and not true abilities.

Abstract: In several meta-analyses, self-estimates of abilities have been shown to correlate surprisingly low with individuals’ real (i.e., psychometrically assessed) abilities. We recently confirmed this in a study where we investigated the accuracy of self- and peer-estimates of six central abilities (verbal, numerical, spatial intelligence, interpersonal and intrapersonal competence, creative/divergent thinking). Here, we describe two studies: In study 1, we first investigated, to which extent self-estimates of adolescents’ central abilities can be predicted from three sources: relevant school grades, the pertinent psychometric ability itself, and personality (big five traits and narcissism). We found that self-estimates are a stronger reflection of the individuals’ personality than their abilities per se. Second, we wanted to assess to what degree (professional) interests, which might guide career decisions in adolescents/young adults, are predicted by self-estimated and psychometrically assessed abilities. We found that professional interests are mostly a function of self-estimates and not of ‘true’ abilities, a finding that we replicated in study 2 with young adults. Given the strong associations between self-estimates and personality and past findings showing that abilities are better predictors of professional success than personality traits are, this might be non-optimal.

Keywords: IntelligenceEmotional intelligenceCreativitySelf-estimatesGradesInterestsAdolescents

Individuals rated their past relationship quality more negatively in retrospect than they saw when in the relation; this bias ma ybe a motivated cognition that helps individuals let go of their ex-partners after a breakup

Ex-appraisal bias: Negative illusions in appraising relationship quality retrospectively. Aidan P. J. Smyth, Johanna Peetz, Adrienne A. Capaldi. Journal of Social and Personal Relationships, February 24, 2020. https://doi.org/10.1177/0265407520907150

Abstract: Cognitive biases are prevalent within the context of romantic relationships. The present research investigated biases about relationships after they have ended. In a longitudinal design (N = 184), individuals reported relationship quality at two time points, as well as rated relationship quality retrospectively. Results supported an ex-appraisal bias: individuals rated their past relationship quality more negatively in retrospect than they had actually reported at the time. This bias was present across participants who stayed together and those who broke up but was three times larger for those whose relationships had ended. This bias may be a motivated cognition that helps individuals let go of their ex-partners after a breakup.

Keywords: Breakup, ex-appraisal bias, ex-partner, motivated cognition, retrospective bias, romantic relationships

Personality, behavioral strengths and difficulties and performance of adolescents with high achievements in science, literature, art and sports

Personality, behavioral strengths and difficulties and performance of adolescents with high achievements in science, literature, art and sports. Kostas A. Papageorgiou et al. Personality and Individual Differences, Volume 160, 1 July 2020, 109917. https://doi.org/10.1016/j.paid.2020.109917

Highlights
•    Personality was more strongly related to behaviour problems than to achievement.
•    Personality may be indirectly linked with achievement via behavior problems.
•    Teacher-awarded grades, but not exam grades, were weakly connected with personality.
•    Teachers gave higher grades to students with ‘desirable’ personality traits.
•    Unlike dark traits, narcissism correlated negatively with internalizing problems.

Abstract: Individual variation in personality is related to differences in behavioral difficulties and achievement in unselected samples, and in samples selected for high achievement in various domains. This is the first study to explore and compare the connections between self-report measures of personality (Big Five and Dark Triad), behavioral strengths and difficulties, and school achievement in four tracks of high-achieving adolescents (N = 1179) selected based on their exceptional performance in: Science, Arts, Sports and Literature. Personality was more strongly related to behavioral strengths and difficulties than to achievement in all tracks. As such, personality traits may be indirectly linked with achievement via behavioral strengths and difficulties. For example, narcissism correlated negatively with behavioral difficulties but did not significantly correlate with achievement. However, achievement was correlated negatively with behavioral difficulties. Network analyses indicated that teacher-awarded grades, but not anonymous exam grades, were weakly connected with personality. Specifically, teachers awarded higher grades to students with more ‘desirable’ personality traits such as high agreeableness. Results also showed track differences in the networks of personality, behavior and achievement. These findings are discussed in the context of personality as a resilience factor against behavioural difficulties and as a contributor to school achievement in gifted adolescents.

Adults spontaneously make moral judgments consistent with the logic of universalization, and children show a comparable pattern of judgment as early as 4 years old

Levine, Sydney, Max Kleiman-Weiner, Laura Schulz, josh tenenbaum, and Fiery A. Cushman. 2020. “Universalization Reasoning Guides Moral Judgment.” PsyArXiv. February 23. osf.io/p7e6h

Abstract: To explain why an action is wrong, we sometimes say: “What if everybody did that?” In other words, even if a single person’s behavior is harmless, that behavior may be wrong if it would be harmful once universalized. We formalize the process of universalization in a computational model, test its quantitative predictions in studies of human moral judgment, and distinguish it from alternative models. We show that adults spontaneously make moral judgments consistent with the logic of universalization, and that children show a comparable pattern of judgment as early as 4 years old. We conclude that alongside other well-characterized mechanisms of moral judgment, such as outcome-based and rule-based thinking, the logic of universalizing holds an important place in our moral minds.

In Spain, the percentage of old drivers (65 an over) has raised from 10.2% in 2007 to 14.3% in 2016; cost of crashes involving 75+ y.o. drivers is 4.3 times higher than accidents involving 65–75 y.o. drivers

Does longevity impact the severity of traffic crashes? A comparative study of young-older and old-older drivers. Mercedes Ayuso, Rodrigo Sánchez, Miguel Santolino. Journal of Safety Research, February 22 2020. https://doi.org/10.1016/j.jsr.2020.02.002

Highlights
• In Spain, the percentage of old drivers (65 an over) has raised from 10.2% in 2007 to 14.3% in 2016.
• Changes in crash severity patterns in the driver’s age of (approximately) 75 years old are statistically significant.
• Male drivers under 75 are more likely to be involved in serious and fatal accidents.
• Gender differences in crash severity among old-older drivers (over 75) are not observed.
• The estimated cost of crashes involving old-older drivers is 4.3 times higher than accidents involving young-older drivers (65–75).
• The expected crash cost can be more than five times higher for old-older drivers than drivers under 65.

Abstract:
Introduction: This article analyzes the effect of driver’s age in crash severity with a particular focus on those over the age of 65. The greater frequency and longevity of older drivers around the world suggests the need to introduce a possible segmentation within this group at risk, thus eliminating the generic interval of 65 and over as applied today in road safety data and in the automobile insurance sector.

Method: We investigate differences in the severity of traffic crashes among two subgroups of older drivers –young-older (65–75) and old-older (75+), and findings are compared with the age interval of drivers under 65. Here, we draw on data for 2016 provided by Spanish Traffic Authority. Parametric and semi-parametric regression models are applied.

Results: We identified the factors related to the crash, vehicle, and driver that have a significant impact on the probability of the crash being slight, serious, or fatal for the different age groups.

Conclusions: We found that crash severity and the expected costs of crashes significantly increase when the driver is over the age of 75.

Practical Applications: Our results have obvious implications for regulators responsible for road safety policies – most specifically as they consider there should be specific driver licensing requirements and driving training for elderly – and for the automobile insurance industry, which to date has not examined the impact that the longevity of drivers is likely to have on their balance sheets.

Keywords: Older driversGroups at riskBodily injuries damagesPolicy implicationsAutomobile insurance

Despite several methods requiring significantly more time facing mortal fear, differences in ability to enact a suicide attempt with a particular method was not associated with fearlessness about death

Fearlessness about death does not differ by suicide attempt method. Brian W. Bauer et al. Journal of Psychiatric Research, February 22 2020. https://doi.org/10.1016/j.jpsychires.2020.02.014

Abstract: Modern theories of suicide, such as the Interpersonal Theory of Suicide, have overcome past conceptual limitations within suicide research by examining factors that help differentiate suicide attempters from those who experience suicidal ideation, but never attempt suicide. One such factor that has been studied extensively is fearlessness about death. Given the varying levels of lethality for different methods used in suicide attempts, an important question is if different levels of fearlessness about death are needed for specific methods. The central aim of this study was to test whether various methods for suicide are associated with different levels of fearlessness about death in a large sample of suicide attempt survivors. Participants were 620 suicide attempt survivors from active military, veteran, and civilian populations. Suicide attempt status was confirmed by two independent raters coding qualitative accounts and participants indicating at least one past attempt with intent to die on other survey items. Results indicated that fearlessness about death does not differ by attempt method and that nearly all methods are statistically equivalent to one another. Despite several methods requiring significantly more time facing mortal fear and severe physical anguish (e.g., cutting, hanging/asphyxiation), as well as certain means being much more lethal (e.g., firearm), differences in ability to enact a suicide attempt with a particular method was not associated with fearlessness about death. This may further indicate the importance of clinicians focusing on practical capability aspects (e.g., means safety, access, comfort with method) with patients at an increased risk for suicide.

Keywords: Capability for suicideSuicide attemptFearlessness about deathEquivalence testing

Pedohebephilia could be considered a form of sexual orientation for age, which includes both sexual and romantic attraction

Sexual Attraction and Falling in Love in Persons with Pedohebephilia. Frederica M. Martijn, Kelly M. Babchishin, Lesleigh E. Pullman & Michael C. Seto. Archives of Sexual Behavior, February 21 2020. https://link.springer.com/article/10.1007/s10508-019-01579-9

Abstract: Few studies of pedophilia or hebephilia have included questions about romantic attraction. We conducted an anonymous online survey of 306 men who self-reported as sexually attracted to children. The majority (72%) of participants reported they had fallen in love with a child in their lifetime. Participants reported greater feelings of attachment to children than feelings of infatuation. Though sexual attraction and falling in love were strongly correlated, they were not synonymous. Participants who reported pedohebephilia (defined in this study as attraction to prepubescent and pubescent children) were more likely to have fallen in love with a child than participants who reported pedohebe-ephebophilia (defined as attraction to prepubescent, pubescent, and post-pubescent minors). Also, participants with an exclusive attraction to children were more likely to have fallen in love with a child than participants who were equally attracted to children and adults. The results of this study were consistent with the suggestion of Seto (2012) that pedohebephilia could be considered a form of sexual orientation for age, which includes both sexual and romantic attraction.

Laboratory: Women avoid competing with men; men seem to anticipate the lower competitiveness of female opponents, as evidenced by their greater tendency to compete against women

Gender and Willingness to Compete for High Stakes. Dennie van Dolder, Martijn J. van den Assem and Thomas Buser. Tinbergen Institute Discussion Paper TI 2020-011/I, Feb 2020. https://papers.tinbergen.nl/20011.pdf

Abstract: We examine gender differences in competitiveness, using a TV game show where the winner of an elimination competition plays a game of chance worth hundreds of thousands of euros. At several stages of the competition, contestants face a choice between continuing to compete and opting out in exchange for a comparatively modest prize. When strategic considerations are absent, we observe the well-known pattern that women are less likely to compete than men, but this difference derives entirely from women avoiding competition against men. When the decision to compete is strategic and contestants should factor in the competitiveness of others, women again avoid competing against men. Men, in turn, seem to anticipate the lower competitiveness of female opponents, as evidenced by their greater tendency to compete against women. Ability differences are unlikely to explain these results. The findings underline the importance of the gender of competitors for the analysis of differences in willingness to compete, and shed new light on the persistent gender gap at the male-dominated higher rungs of the career ladder.

JEL: D91, J16
Keywords: gender differences, competitiveness, willingness to compete, game show

6. Conclusion and discussion

The present paper examined gender differences in willingness to compete for high stakes, using a TV
game show where the winner of an elimination competition plays a game of chance worth hundreds
of thousands of euros. The amounts that are at stake in this real-life setting are much closer to the
sums involved in promotion competitions at the top of the labor market than the financial rewards
that are commonly employed in laboratory experiments.
We focused on two different games. In the first, contestants choose between competing in the next
elimination game and opting out for a prize. This decision resembles the tournament-entry decision
that subjects typically make in lab experiments. In line with the picture that emerges from the
experimental literature, we find that women are twice as likely as men to avoid the competition. The
comparatively high opt-out rate of women, however, derives entirely from situations where they will
face predominantly male opponents. This suggests that women have a particular dislike of competing
against men, rather than a more general dislike of competition. In this non-strategic game, men do not
appear to condition their behavior on the gender of their opponents.
In the second game one question determines the last elimination, unless one of the two remaining
contestants voluntarily accepts an opt-out prize. This head-to-head game is relatively complex,
because the optimal choice depends on the anticipated behavior of the opponent. The results show
that both genders avoid competing against a male opponent in this strategic setting. The same pattern
arises in the strategic game analyzed in the Appendix. This pattern confirms the result for the first
game that women avoid competing against men, and suggests that in strategic interactions men
anticipate a lower willingness to compete among their female opponents. In line with the results for
the first game, there is no evidence of a main effect of gender on competitiveness.
Altogether, the results confirm that gender differences in willingness to compete also occur in
situations where the stakes are very high, but they also indicate that the stereotypical image and
widely-held belief that women are less competitive than men is too simplistic. The findings show the
importance of the gender of competitors and of the presence of strategic interaction: women appear
to dislike competing against men, and men appear to exploit this when there is strategic interaction.
Hitherto, the literature on gender differences in willingness to compete has largely ignored these two
factors. Exceptions are Booth and Nolen (2012) and Geraldes (2018), who similarly find that women
avoid competing against men. Such a dislike is in line with evidence that women perform worse when
they compete against men (Gneezy, Niederle and Rustichini, 2003; Günther et al., 2010; Backus et al.,
2016; de Sousa and Hollard, 2016; Booth, Cardona-Sosa and Nolen, 2018; Booth and Yamamura, 2018).
Strategic interaction is typically ruled out by design in willingness-to-compete experiments.
Research somewhat removed from the willingness-to-compete literature indirectly supports our
conclusion about the importance of opponent gender in strategic interactions. Babcock et al. (2017)
show that women are more likely than men to volunteer for an undesirable task when interacting in
mixed-gender groups, but not when interacting in single-gender groups. Booth and Yamamura (2018)
study Japanese speedboat races and find that men adopt a more aggressive racing style in mixedgender races than in single-gender races, whereas women act less aggressively in mixed-gender races
than in single-gender races. Hernandez-Arenaz and Iriberri (2018) investigate bargaining behavior in a
Spanish TV game show and find that women ask less from men than from women.
Our setting differs in a number of ways from that of a traditional laboratory experiment. In addition to
the markedly higher stakes, the subject pool that we observe is much more diverse, and because of
the presence of a large audience and cameras, our contestants’ decisions are observed by many and
subject to considerable public scrutiny. A benefit of the diverse pool of contestants is that we can also
explore how competitiveness varies with age. We consistently find a u-shaped relation, with people
who are in their forties displaying the lowest opt-out propensity. Mayr et al. (2012) find a similar
relation between age and competitiveness among subjects in an incentivized experiment. Flory et al.
(2018) and Buser, Niederle and Oosterbeek (2020), however, report different age patterns.
A benefit of the public nature of the competition, is that this feature is shared by many consequential
real world competitions. In the political arena and upper echelons of the corporate world, for example,
people face considerable public scrutiny when they compete for top positions. This is another
argument for why our naturally occurring setting is much more similar to such real-world situations
than anonymous, low-stakes laboratory experiments. Because opting out of the competition ends
public observability and choosing to compete extends it, a difference in the attitudes of men and
women towards public observability would obfuscate the relation between gender and
competitiveness. To the best of our knowledge, the only paper that studies the impact of public
observability on competitiveness is Buser, Ranehill and van Veldhuizen (2019). They find suggestive
evidence that public observability increases men’s willingness to compete, but conclude that public
observability does not alter the magnitude of the gender gap in willingness to compete in an
economically or statistically significant way. This possible confound also occurs in many real-life
settings, but cannot explain why women display a dislike of competing against men and why men are
more competitive when they face women in a strategic setting.
Similar to the tasks that are typically used in willingness-to-compete experiments, the questions that
are central in the elimination competition are often numerical or arithmetic in nature. This similarity
facilitates the comparison of our results with those of previous studies. Research on competitiveness
often intentionally uses such tasks because mathematics is a stereotypically male area, which brings
the research closer to competitive situations in male-dominated workplaces or male-connotated areas
such as management (Niederle and Vesterlund, 2011). Although we cannot entirely rule out that our
results are partly driven by a gender difference in the ability to answer the questions, none of the
additional analyses of our data provide evidence that the quiz questions actually favor men. Second,
based on research into math performance and research into recall of factual information, there is little
reason to believe that such a difference holds true for the general population (Herlitz et al., 1997;
Nilsson, 2003; Hyde et al., 2008; Lindberg et al., 2010). Last, even if any gender difference would exist
among the initial pool of contestants, it would be relatively small among those we study because
weaker contestants are less likely to reach the stages of interest.
Of course, contestants may have held non-rational expectations about their own ability and that of
others, possibly inspired by stereotypical beliefs about the performance of men and women on math
questions. Indeed, in experimental work that uses a neutral or stereotypically female type of task,
competitiveness differences between men and women are sometimes, but not always, weak or absent
(Große and Riener, 2010; Shurchkov, 2012; Dreber, von Essen and Ranehill, 2014; Wozniak, Harbaugh
and Mayr, 2014). Stereotype-biased beliefs about performance may explain why women display a
relatively low propensity to compete against men in all the games that we study, and why men display
a relatively high propensity to compete against women when the game is strategic. This explanation,
however, is not supported by the behavior of men in the first game: there is no evidence that men are
especially eager to compete against women. If anything, men are more likely to opt out against women
than against men in this game.
A possible concern about our findings is that their generalizability might be negatively affected by
selection effects. Selection procedures are inevitable in any lab experiment or field setting, and could
potentially bias comparisons of the behavior of men and women (Larkin and Pines, 2003; Reback and
Stowe, 2011; Hogarth, Karelaia and Trujillo, 2012). Unlike contestants in most other game shows,
however, contestants in our elimination competition do not need to self-select into auditions and are
not screened and then selected by producers prior to their participation. All have won their ticket
through the popular Dutch Postcode Lottery. Even for competition-averse individuals, using this ticket
is attractive: in addition to the lucrative possibility of becoming the finalist, contestants can win many
other large prizes. Nevertheless, subjects in our study are not selected perfectly at random: all are
lottery players who were able to attend the recording, and couples might send the best or most
competitive of the two of them. Still, as a group the subjects in our study do resemble a cross-section
of the general population much more closely than subjects in most lab experiments and other field
studies do. More importantly, it is not clear how selection mechanisms could explain that the
competitiveness of men and women depends on the gender of their opponent.
Our study finds that women avoid competition against men, but remains silent on the underlying
causes of this behavior. According to the literature, differences in reluctance to compete can be driven
by differences in risk attitudes, (over)confidence, and intrinsic attitudes towards competition.
However, even in controlled experiments, and even without strategic interaction and consideration of
the role of the gender of opponents, careful disentangling of the possible determinants of
competitiveness has proven to be methodologically challenging (van Veldhuizen, 2018; Gillen,
Snowberg and Yariv, 2019). Our field data is not rich enough for delving into the possible explanations,
but it seems implausible that risk preferences depend on the gender of the opponents. This leaves
opponent-dependent confidence in performance and intrinsic opponent-dependent attitudes towards
competition as the most likely drivers: women could be less confident about their performance in a
competition against men, or have a more deeply rooted, intrinsic aversion to competing against men.
Such a specific response to the opponent’s gender can, in turn, be partly determined by the culture in
which people grow up (Gneezy, Leonard and List, 2009; Andersen et al., 2013; Booth et al., 2019;
Zhang, 2019).
Research into the effect of social class and ethnicity on competitiveness suggest that gender
differences in competitiveness—including those identified in the present study—may derive from a
more general phenomenon, where willingness to compete relates to social power and status. Almås
et al. (2016b) find that gender differences in competitiveness arise between boys and girls from
families with a high socioeconomic status only, and not between those who are from families with a
low socioeconomic status. Siddique and Vlassopoulos (2019) report that people from an ethnic
minority group are more likely to compete when their competitors are all co-ethnic than when their
competitors are predominantly from the majority group.
Regardless of the possible psychological mechanisms, the finding that women avoid competing against
men has the important implication that male dominance in a professional environment becomes selfperpetuating. This is especially the case if there is strategic interaction, where those who compete are
better off when others abstain from competing. In such a setting, women can expect more pushback
from both male and female competitors. At the higher rungs of the career ladder, where
overrepresentation of men and strategic interaction are both ubiquitous, affirmative action may be
necessary to alter the status quo.