Rats & mice show comparable levels of emotional contagion, & an equivalent contagion response to familiar and unfamiliar conspecifics

Towards a unified theory of emotional contagion in rodents—A meta-analysis. Julen Hernandez-Lallement, Paula Gómez-Sotres, Maria Carrillo. Neuroscience & Biobehavioral Reviews, October 3 2020. https://doi.org/10.1016/j.neubiorev.2020.09.010

Highlights

• Rats and mice show comparable levels of emotional contagion, however, only mice strain-specific differences in emotional contagion response.

• Rats and mice show an equivalent contagion response to familiar and unfamiliar conspecifics.

• Prior experience with an emotional inducing stimulus significantly increases fear contagion response in rats but not in mice.

• Social testing condition influences the level of contagion: animals tested alone show reduced contagion compared to animals tested in a group.

Abstract: Here we leverage 80 years of emotional contagion research in rodents and perform the first meta-analysis on this topic. Using 457 effect sizes, we show that, while both rats and mice are capable of emotional contagion, there are differences in how various factors modulate empathy in these species: 1) only mice show strain-specific differences in emotional contagion response; 2) although rats and mice have equivalent contagion response to familiar and unfamiliar individuals, our results show that familiarity length is negatively correlated with level of contagion in rats only; 3) prior experience with emotional stimuli almost doubles fear contagion response in rats while no changes are detected in pre-exposed mice; 4) both mice and rats tested alone show comparable reduced contagion compared to animals tested in a group; 5) emotional contagion is reduced in animals from both species missing one sensory modality compared to situations where all sensory modalities are recruited during emotional contagion. Lastly, we report similar patterns of brain activation during emotional contagion in rats and mice.

Keywords: Emotional contagionMeta-analysisRodentsEmpathy

4. Conclusion and limitations

4.1. Updating current models of emotional contagion

While a high number of reviews attempting to summarize the literature on emotional contagion in rodents were published in recent years (Keysers and Gazzola, 2016; Meyza et al., 2016; Keum and Shin, 2016; Sivaselvachandran et al., 2016; Mogil, 2012; Lukas and de Jong, 2016; Keum and Shin, 2019), one article in particular went one step further and proposed a classification of experimental approaches used in the field (Panksepp and Panksepp, 2013a). This classification distinguished a variety of phenomenon such as contagion, social analgesia, social buffering, social priming, behavioral matching and social transfer. In the current meta-analysis, we updated and simplified this classification based on our revised inclusion criteria for studies measuring emotional contagion: ‘a study measuring a behavioral response associated with (indirectly -in absence of- and directly -in presence of others-) the emotional cues of other individuals’. This means that all the phenomena mentioned above, per our definition, fall under the emotional contagion umbrella. One illustrative example is the case of social buffering, where a distressed animal shows reduced fear when paired with a neutral non-distressed conspecific. In these cases, we considered the observed phenomenon as emotional contagion from an animal in a neutral emotional state to one in a fearful state. This approach allowed us to unify different paradigms, and seemingly diverse approaches on rodent empathy into a single model. Our classification had additional key differences with the classification proposed by Panskepp & Panksepp (Panksepp and Panksepp, 2013a): 1) contagion can occur without the direct presence of an individual (e.g., through a cotton boll soaked with urine of a fearful animal); 2) emotional contagion paradigms consist of three phases: pre-exposure, emotional transfer and measure of emotional contagion; 3) the term emotional transfer refers to the point in time in which the emotional state from one individual is contaged to another (measurement time could happen during or after emotional transfer); 4) measurements of emotional contagion had to recruit an emotional observable response; if they failed to do so (such as memory effects), they were not considered direct measurements of emotional contagion but rather secondary processes related to emotional contagion. All the studies included in the current meta-analysis fall under this classification.

4.2. Limitations

While we strived to reduce the number of arbitrary decisions that needed to be made (by devising a clear methodology and procedures in the decision process), inevitably, we did encounter difficult choices at different stages of the process. In particular, for each study, we were confronted with interpreting whether the reported data was a direct measure of emotional contagion, or rather a secondary process triggered by emotional contagion. The lack of clear definitions and unity in the field made it challenging in deciding which data was indeed relevant for this meta-analysis. In order to guide our decisions, we elaborated a framework through which each study was pipelined to take a decision on whether the effect size reflected emotional contagion-related data. For instance, research performed on social transmission of taste aversion can be arguably included in the emotional contagion field, since, typically in these paradigms, one animal undergoes an aversive emotion (taste), which is thereafter transmitted to a naïve conspecific through interactions. However, these publications were not included in this meta-analysis due to the fact that the aversive emotion experienced by the demonstrator was often not measured and quantified, nor was the actual transfer of emotion. Similar issues were encountered in studies where emotional contagion was used as a tool, rather than a measure, to study how observing the distress of others affected cognitive abilities later in time, such as memory and learning (Nowak et al., 2013; Ito et al., 2015a). Albeit these are important effects of emotional contagion in other neural processes and behaviors, they are not a direct measurement of emotional contagion, and as such were excluded from the main analysis.

However, we find it important to emphasize the caveats of our approach by pointing out other missing aspects of the emotional contagion literature. For instance, the filters used in this study failed to capture articles on mother-pup interaction and the emotional transfer inherent to such social systems (Moriceau and Sullivan, 2006; Barr et al., 2009). Future meta-analytic work on this topic could increase their search filter range to include such studies and encompass even more variability in rodent emotional contagion.

It should also be noted that our filters might have failed to include articles where similar processes were studied but other wording was used. It is notable that rodent emotional contagion is a controversial topic (Balter, 2011) and several studies have framed their results in terms of stress-related processes instead of emotional contagion (Breitfeld et al., 2015; Zalaquett and Thiessen, 1991; Mackay-Sim and Laing, 1981). While we believe that the high number of effect sizes and studies included in this meta-analysis already allow for careful conclusions to be drawn, future endeavors should carefully increase the granularity of their filters to encompass studies that investigated similar processes under a different framework.

Another limitation of our work is the low number of effect sizes present in some distributions. For instance, the low number of effect sizes reported in females makes it difficult to conclude on the results reported here, that is, that sex does not modulate emotional contagion. Similar parsimony should be used when interpreting effect sizes reported in different strains. For instance, the differences reported between CD-1 and CF-1 mice, two very close strains, are quite surprising. One likely explanation for this (and other) differences might lie in the experimental paradigm used, which differed between strains. These discrepant results suggest that additional, more granular variables should be added to future meta-analysis. For instance, an attempt at classifying experimental paradigms to identify contexts and situations where emotional contagion might be more salient would allow to associate differences in effect sizes to experimental manipulations rather than to species, strains or other parameters.

This meta-analysis revealed that, although, emotional contagion can occur in response to both positive and negative emotions, as already noted by (Panksepp and Panksepp, 2013c), to date nearly all studies investigating emotional contagion in rodents use negative stimuli to trigger emotional transfer, which could be due to the fact that in rodent empathy research negative reinforcers are traditionally used. This observation stresses the need to use positive reinforcers to study the other side of rodent empathy, as already performed in some studies (Willuhn et al., 2014b; Kashtelyan et al., 2014b; Lichtenberg et al., 2018), and more generally in the field of prosocial behavior (Lichtenberg et al., 2018; Márquez et al., 2015; Hernandez-Lallement et al., 2016b, 2020). A promising avenue would lie in studies that directly compare the effects of positive and negative reinforcers, although we acknowledge that developing comparable positive and negative stimulus is a challenge given the higher saliency and reinforcing power of negative stimuli. On the other hand, it is important to consider the possibility, that the under reporting of studies using positive stimuli could be due to lack of effect of this type of stimuli and bias to report null effects.

A final limitation that we encountered was the incomplete reporting of information, namely, the methods section. We noticed that some variables more likely to not be properly reported such as age and number of days that observers and demonstrators were related to each other, with 13 % and 21 % of overall missing values per category respectively. In addition, our quantitative analysis suggested that randomization, blinding and sample size calculations are seldom reported (and/or done) in studies in the field, which overall reduces the results quality.

4.3. Conclusion

Overall, this is the first meta-analysis and systematic review conducted to date on the field of rodent emotional contagion. In this meta-analysis we develop an umbrella definition of emotional contagion that covers a large rage of studies investigating this response. We also developed a classification model that allowed us to unify a range of existing paradigms used to investigate emotional contagion. Within this model we identified key parameters that have a modulatory effect on emotional contagion and that can be used for optimizing the design of future studies in the field. However, we underscore that many differences reported here should be taken cautiously since the lack of effect sizes and major differences in experimental paradigms could still account for effects we report in this meta-analysis. We also identify a range of brain regions that can be used as targets for further to further our understanding of the neural mechanisms of emotional contagion. Lastly, this meta-analysis also identifies gaps in knowledge and potential research areas of interest.

Italy: War, Socialism and the Rise of Fascism

War, Socialism and the Rise of Fascism: An Empirical Exploration. Daron Acemoglu, Giuseppe De Feo, Giacomo De Luca, Gianluca Russo. NBER Working Paper No. 27854, September 2020. https://www.nber.org/papers/w27854

Abstract: The recent ascent of right-wing populist movements in many countries has rekindled interest in understanding the causes of the rise of Fascism in inter-war years. In this paper, we argue that there was a strong link between the surge of support for the Socialist Party after World War I (WWI) and the subsequent emergence of Fascism in Italy. We first develop a source of variation in Socialist support across Italian municipalities in the 1919 election based on war casualties from the area. We show that these casualties are unrelated to a battery of political, economic and social variables before the war and had a major impact on Socialist support (partly because the Socialists were the main anti-war political movement). Our main result is that this boost to Socialist support (that is “exogenous” to the prior political leaning of the municipality) led to greater local Fascist activity as measured by local party branches and Fascist political violence (squadrismo), and to significantly larger vote share of the Fascist Party in the 1924 election. We document that the increase in the vote share of the Fascist Party was not at the expense of the Socialist Party and instead came from right-wing parties, thus supporting our interpretation that center-right and right-wing voters coalesced around the Fascist Party because of the “red scare”. We also show that the veterans did not consistently support the Fascist Party and there is no evidence for greater nationalist sentiment in areas with more casualties. We provide evidence that landowner associations and greater presence of local elites played an important role in the rise of Fascism. Finally, we find greater likelihood of Jewish deportations in 1943-45 and lower vote share for Christian Democrats after World War II in areas with greater early Fascist activity.

Studies found that condom-use discounting is elevated in high-risk substance use populations & is sensitive to context (e.g., partner desirability); administering cocaine & alcohol increased condom-use discounting

Johnson, M. W., Strickland, J. C., Herrmann, E. S., Dolan, S. B., Cox, D. J., & Berry, M. S. (2020). Sexual discounting: A systematic review of discounting processes and sexual behavior. Experimental and Clinical Psychopharmacology, Oct 2020. https://doi.org/10.1037/pha0000402

Rolf Degen's take: https://twitter.com/DegenRolf/status/1312038923296804865

Abstract: Behavioral processes underlying sexual behavior are important for understanding normal human functioning and risk behavior leading to sexually transmitted infections (STIs). This systematic review examines delay and probability discounting in human sexual behavior through synthesis of 50 peer-reviewed, original research articles. Sixteen studies focusing exclusively on monetary delay discounting found small effect size positive correlations with sexual risk behaviors. Eleven studies examined delay or probability discounting of sexual behavior itself using tasks that varied duration, frequency, or quality of sex to determine value. Results show delay and uncertainty of sex causes systematic decreases in value. These studies also show consistent medium effect size relationships between sexual discounting measures and sexual health and substance use, supporting utility above and beyond monetary discounting. Twenty-three studies have modeled clinically relevant decision-making, examining effects of delay until condom availability and STI contraction probability on condom use. Observational and experimental designs found condom-use discounting is elevated in high-risk substance use populations, is sensitive to context (e.g., partner desirability), and is more robustly related to sexual risk compared with monetary discounting or condom use decisions when no delay/uncertainty was involved. Administering cocaine, alcohol, and, for some participants, methamphetamine increased condom-use discounting with minimal effect on monetary discounting or condom use when no delay/uncertainty was involved. Reviewed studies robustly support that sexual behavior is highly dependent on delay and probability discounting, and that these processes strongly contribute to sexual risk. Future research should exploit these systematic relationships to design behavioral and pharmacological approaches to decrease sexual risk behavior.

Social media use seems to hinder rather than enhance an individual’s learning about politics, because it fosters the perception that one no longer needs to actively seek news in order to stay informed (i.e., news-finds-me perception)

Probing the Mechanisms Through Which Social Media Erodes Political Knowledge: The Role of the News-Finds-Me Perception. Sangwon Lee. Mass Communication and Society, Oct 1 2020. https://doi.org/10.1080/15205436.2020.1821381

Rolf Degen's take: https://twitter.com/DegenRolf/status/1311978431819722753

ABSTRACT: This study examines the causal effects of social media use on political knowledge as well as the underlying mechanisms through which such an effect occurs. The findings suggest that social media use hinders rather than enhances an individual’s learning about politics, because social media use fosters the perception that one no longer needs to actively seek news in order to stay informed (i.e., news-finds-me perception), and this in turn may have an adverse effect on an individual’s learning about politics. However, those who use traditional forms of media to a substantial degree to complement their news consumption via social media are less negatively affected than those who do not.

Spiritual training intends to reduce self‐enhancement, but the self‐enhancement motive is so powerful & deeply ingrained that it hijacks methods intended to transcend the ego, boosting superiority feelings

An Exploration of Spiritual Superiority: The Paradox of Self‐Enhancement. Roos Vonk  Anouk Visser. European Journal of Social Psychology, October 1 2020. https://doi.org/10.1002/ejsp.2721

Rolf Degen's take: https://twitter.com/DegenRolf/status/1311888149015126017

Abstract: Spiritual training is assumed to reduce self‐enhancement, but may have the paradoxical effect of boosting superiority feelings. It can, thus, operate like other self‐enhancement tools and contribute to a contingent self‐worth that depends on one’s spiritual accomplishments. In three studies (N=533, N=2223, N=965), a brief measure of spiritual superiority showed good internal consistency and discriminant validity. As predicted, it was distinctly related to spiritual contingency of self‐worth, illustrating that the self‐enhancement function of spirituality is similar to other contingency domains. It was correlated with self‐esteem and, more strongly, with communal narcissism, corroborating the notion of spiritual narcissism. Spiritual Superiority scores were consistently higher among energetically trained participants than mindfulness trainees and were associated with supernatural overconfidence and self‐ascribed spiritual guidance. Our results illustrate that the self‐enhancement motive is powerful and deeply ingrained so that it can hijack methods intended to transcend the ego and, instead, adopt them to its own service.

Check also Petersen, Michael Bang, and Panagiotis Mitkidis. 2019. “A Sober Second Thought? A Pre-registered Experiment on the Effects of Mindfulness Meditation on Political Tolerance.” PsyArXiv. October 20. https://www.bipartisanalliance.com/2019/10/analyses-of-data-from-pilot-experiment.html

‘I Do Not Exist’: Pathologies of Self Among Western Buddhists. Judith Pickering. Journal of Religion and Health, June 2019, Volume 58, Issue 3, pp 748–769. https://www.bipartisanalliance.com/2019/07/i-do-not-exist-pathologies-of-self.html

Mindfulness not related to behavioral & speech markers of emotional positivity (or less negativity), interpersonally better connected (quality or quantity), or prosocial orientation (more affectionate, less gossipy or complaining):

Dispositional mindfulness in daily life. Deanna M. Kaplan, L. Raison, Anne Milek, Allison M. Tackman, Thaddeus W. W. Pace, Matthias R. Mehl. PLOS, https://www.bipartisanalliance.com/2018/11/mindfulness-not-related-to-behavioral.html

Those who fear being single generally do not have difficulty attracting prospective partners; is this so because daters cannot detect fear of being single, or because detected fear of being single does not hinder desirability?

Detectability and Desirability of Fear of Being Single in Online Dating Profiles. Stephanie S. Spielmann  Kevin P. Gahman. Journal of Personality, September 30 2020. https://doi.org/10.1111/jopy.12597

Abstract

Objective: Those who fear being single generally do not have difficulty attracting prospective partners. The present research explores whether this is because daters cannot detect fear of being single, or because detected fear of being single does not hinder desirability.

Method: In Study 1 (N=235, 60% women, Mage=36.9), participants created dating profiles then rated the desirability of profiles depicting high vs. low fear of being single (high narcissism control). In Study 2 (N=176, 69% women, Mage=21.4), participants evaluated fear of being single and desirability of actual profiles.

Results: Differences in fear of being single were detectable. Furthermore, detecting higher fear of being single predicted lower romantic desirability. Desirability ratings were due, in part, to estimating lower physical attractiveness (Study 2). Perceivers’ own fear of being single moderated effects, such that those higher in fear of being single were not deterred by higher fear of being single.

Conclusions: Fear of being single may be detectable when online dating, but desirability of detected fear of being single varies depending on perceiver traits and may be driven in part by misperceptions of physical attractiveness. This research sheds light on challenges for those who fear being single as they attempt to attract mates.

This paper identifies the degree to which scientists are willing to change the direction of their work in exchange for resources

American Economic Journal: Applied Economics. Oct 2020, Vol. 12, No. 4: Pages 103-134. The Elasticity of Science. Kyle Myers. https://pubs.aeaweb.org/doi/pdfplus/10.1257/app.20180518

Abstract: This paper identifies the degree to which scientists are willing to change the direction of their work in exchange for resources. Data from the National Institutes of Health are used to estimate how scientists respond to targeted funding opportunities. Inducing a scientist to change their direction by a small amount—to work on marginally different topics—requires a substantial amount of funding in expectation. The switching costs of science are large. The productivity of grants is also estimated, and it appears the additional costs of targeted research may be more than offset by more productive scientists pursuing these grants. (JEL H51, I10, I23, O31, O33)

Multiple genome-wide significant loci and genes were identified and polygenic score prediction of suicide death case-control status was demonstrated

Genome-Wide Association Study of Suicide Death and Polygenic Prediction of Clinical Antecedents. Anna R. Docherty et al. The American Journal of Psychiatry, Oct 1 2020. https://doi.org/10.1176/appi.ajp.2020.19101025

Abstract

Objective: Death by suicide is a highly preventable yet growing worldwide health crisis. To date, there has been a lack of adequately powered genomic studies of suicide, with no sizable suicide death cohorts available for analysis. To address this limitation, the authors conducted the first comprehensive genomic analysis of suicide death using previously unpublished genotype data from a large population-ascertained cohort.

Methods: The analysis sample comprised 3,413 population-ascertained case subjects of European ancestry and 14,810 ancestrally matched control subjects. Analytical methods included principal component analysis for ancestral matching and adjusting for population stratification, linear mixed model genome-wide association testing (conditional on genetic-relatedness matrix), gene and gene set-enrichment testing, and polygenic score analyses, as well as single-nucleotide polymorphism (SNP) heritability and genetic correlation estimation using linkage disequilibrium score regression.

Results: Genome-wide association analysis identified two genome-wide significant loci (involving six SNPs: rs34399104, rs35518298, rs34053895, rs66828456, rs35502061, and rs35256367). Gene-based analyses implicated 22 genes on chromosomes 13, 15, 16, 17, and 19 (q<0.05). Suicide death heritability was estimated at an h2SNP value of 0.25 (SE=0.04) and a value of 0.16 (SE=0.02) when converted to a liability scale. Notably, suicide polygenic scores were significantly predictive across training and test sets. Polygenic scores for several other psychiatric disorders and psychological traits were also predictive, particularly scores for behavioral disinhibition and major depressive disorder.

Conclusions: Multiple genome-wide significant loci and genes were identified and polygenic score prediction of suicide death case-control status was demonstrated, adjusting for ancestry, in independent training and test sets. Additionally, the suicide death sample was found to have increased genetic risk for behavioral disinhibition, major depressive disorder, depressive symptoms, autism spectrum disorder, psychosis, and alcohol use disorder compared with the control sample.

Mates high in physical attractiveness are in short supply, which means that not all people are able to find mates who are sufficiently attractive

Mating Decisions in the Absence of Physical Attraction. Kaitlyn P. White, Peter K. Jonason & Laith Al-Shawaf. Adaptive Human Behavior and Physiology, Sep 30 2020. https://link.springer.com/article/10.1007/s40750-020-00152-2

Abstract

Objective: Mates high in physical attractiveness are in short supply, which means that not all people are able to find mates who are sufficiently attractive. Threshold models of mate preferences suggest that when physical attractiveness minimums are not reached, other traits possessed by a potential partner may play a lesser role in mate choice. However, few studies have sought to understand mating decisions when those minimums are not met.

Methods: In this experiment (N = 186), participants rated images of (pre-rated) unattractive opposite-sex others for long-term and short-term relationships after learning dealbreaker or dealmaker information.

Results: While participants did not find targets highly desirable or physically attractive (as a stimulus check), men were more willing than women to have casual sex, and that men and women reported similar desirability ratings towards long-term partners. Learning dealbreakers was associated with less desire for the targets than dealmakers, but women’s lack of interest was insensitive to mating context, whereas men found the target especially undesirable in the long-term context. Additionally, men were willing to consider a long-term relationship with a physically unattractive partner who possessed dealmakers, but not one who possessed dealbreakers.

Conclusions: Our discussion focuses on men and women’s mating decisions when potential partners fail to meet minimum thresholds for physical attractiveness. Future research is needed to explore the magnitude of the effect of meeting or failing to meet one’s minimum thresholds for physical attractiveness.

Discussion

Most research on mate selection has concentrated on what people view as appealing in a potential mate (Buss 1989; Confer et al. 2010; Li et al. 2002; Li and Kenrick 2006) rather than unappealing (Jonason et al. 2015, 2020a, b; Stewart-Williams et al. 2017). Parental investment theory suggests that the costs of making mating mistakes is higher for females, the sex with the greater minimum obligatory parental investment (Trivers 1972). Given this imbalance between the sexes, selection pressures may have fashioned different mating psychologies for men and women (Buss and Schmitt 1993). Research on attractiveness thresholds suggests that men consider physical attractiveness to be an essential characteristic in a prospective mate. This suggests that men will be less open to dating someone who is below average in physical attractiveness (Gangestad et al. 2006; Li et al. 2002). However, error management theory (Haselton and Buss 2000; Perilloux 2014) suggests that, whenever mating options are sub-par, men may be willing to overlook their preferences for physical attractiveness to not miss out on a reproductive opportunity, especially if the mating context is short-term and the prospective mate possesses dealmakers (Webster et al. 2020). In this study, we examined men and women’s ratings of prospective mates in both long-term and short-term contexts when these mates were physically unattractive and possessed either favorable (i.e., dealmakers) or unfavorable (i.e., dealbreakers) characteristics.

Both men and women reported low levels of interest in both short-term and long-term relationships with physically unattractive people. This supports past research suggesting that both men and women value physical attractiveness in potential mates (Buss 1989; Li and Kenrick 2006) and that men consider at least average physical attractiveness to be a crucial characteristic of a partner (Buss and Schmitt 1993; Li et al. 2002; Li and Kenrick 2006; Regan 1998a, b). Consistent with sexual strategies theory, men were more willing than women were to engage in a short-term sexual relationship (Buss and Schmitt 1993), a finding that extended even to prospective mates of low physical attractiveness (H1). This is also consistent with error management theory (Haselton and Buss 2000; Perilloux 2014) in that, even though men tend to place greater value on physical attractiveness (Buss and Schmitt 1993; Confer et al. 2010; Jonason et al. 2012b; Li et al. 2002; Regan 1998a, b), in a low risk, short-term context, men were willing to form a relationship with a physically unattractive mate to avoid missing out on a mating opportunity (Jonason et al. 2020a, b; Regan 1998a, b; Webster et al. 2020). In addition, both sexes reported lower levels of interest in prospective mates after learning that the potential mate possessed dealbreakers rather than dealmakers (H4). This was true in both the long-term and short-term mating contexts. Further, in the short-term context, men reported greater attraction than women to physically unattractive potential mates with either dealmakers or dealbreakers. However, men were only more willing than women to consider a long-term relationship with a physically unattractive person if that person possessed dealmakers.

If men are more willing to lower their standards to avoid lost mating opportunities and women maintain higher standards in mating regardless of context, men may be sensitive to contextual differences, but women should find unattractive partners undesirable regardless of context. As predicted, women were less willing than men to date physically unattractive prospective mates (H3). Women also showed low levels of interest in a physically unattractive partner no matter the mating context or information learned (H2). This may appear to contradict existing research showing that men place more of a premium on physical attractiveness than women do (Li et al. 2002), but this is likely attributable to the fact that we examined mating decisions when confronted with a physically unattractive potential partner, rather than examining differences between the sexes in the emphasis they place of various characteristics. Indeed, these findings are consistent with existing theory and research highlighting how selective women are in their mating decisions (Buss 2016). This aligns with sexual strategies theory, and perhaps also with error management theory (Haselton and Buss 2000; Perilloux 2014) in that mating mistakes for women are costly enough that the safer error for women may be to avoid any kind of relationship with an undesirable partner. Women’s selectivity across a broad range of traits and mating contexts may aid in carefully screening prospective mates and avoiding entanglements with partners of low mate value (Jonason et al. 2015).

Limitations and Conclusions

The present study is the first to evaluate dealbreakers in relationships with a standardized method for assessing interest in short-term and long-term relationships in the absence of physical attractiveness. Even so, several limitations apply. The first limitations pertain to the W.E.I.R.D. (Henrich et al. 2010) nature of the sample and the disparity between men and women in the sample. As is typical in this type of research, more women than men were willing to participate. Although we found an interaction between mating context and sex, further analysis revealed no difference between long-term and short-term ratings in men or women. This may have resulted from the small percentage of men in the sample. However, because our primary aim in this study was to evaluate dealbreakers and dealmakers in relationships, our a priori power analysis focused on dealbreaker/dealmaker effect sizes. Although our results are consistent with our hypotheses, without replication in an independent, larger sample we cannot be certain of the generalizability or robustness of our findings. However, the fact that our results are consistent with established theories enhances the trustworthiness of our results and undercuts concerns about sample size imbalance or the small—by modern standards—sample size.

Second, physical attractiveness acts as a threshold trait (Kenrick et al. 1990; Li et al. 2002) meaning that the absence of physical attraction often operates as a dealbreaker in both sexes (Jonason et al. 2015). By holding attractiveness low and constant, we (1) isolated effects for nonphysical characteristics when physical attractiveness of the potential mate is low and (2) standardized our materials (Jonason and Antoon 2019). In fact, the generally low desirability ratings may reveal just how little nonphysical qualities—no matter their valence—in a potential short-term or long-term mate influence mate choice when attractiveness falls below threshold. Future research might manipulate the attractiveness of the targets to estimate the magnitude of the effect of meeting (or not) minimum thresholds for physical attractiveness (Jonason et al. 2019).

Third, we assessed romantic interest in short-term and long-term mating contexts in relation to 10 dealbreakers and 10 dealmakers when randomly paired with one of eight photos of physically unattractive people. Each of the items may have its own, distinct effects worthy of independent investigation. We used the composite approach rather than item analyses to avoid Type 1 error inflation and so that we could say something more general about decision-making in romantic relationships (Jonason et al. 2020a, b). Therefore, further research is needed at the item-level to examine how each individual dealmaker and dealbreaker affects interest in physically unattractive partners. Moreover, other lists of dealbreakers and dealmakers might be worth considering to evaluate the generalizability of these effects.

Finally, although our picture selection process was reasonably systematic, some limitations were present. We exclusively used pictures of people who appeared to be of Caucasian ethnicity, which limits the generalizability of our findings to other ethnicities. In addition, although the pictures used were pre-rated for attractiveness by numerous independent raters from the source, the attractiveness ratings used were still subjective, as opposed to more objective indices such as fluctuating asymmetry (Little et al. 2011). However, the participants’ mean ratings of attractiveness suggest that, as we had intended, our participants considered the people in the pictures to be of below average physical attractiveness. Despite these limitations, we have provided a novel test of sex differences in mate choice as a function of relationship context and the type of information people learn as they get to know new, potential partners.

One of the most contentious areas in mate choice research is about the role and origin of physical attractiveness preferences (Li and Metzler 2015; Zentner and Eagly 2015). Arguments rage over the function, origin, and consequences of being physically attractive in and outside of mate choice contexts. Evolutionary psychologists point to the adaptive utility of a preference for physical attractiveness, whereas sociocultural models sometimes treat preferences for physical attraction as arbitrary. We decided to strip away physical attraction and learn about the mate selection process in men and women across contexts in the absence of physical attraction. In doing so, we replicated prior findings demonstrating that men are more interested in short-term relationships than women are, and the sexes reported similar desirability ratings towards long-term partners (Buss and Schmitt 1993). We also found that even when prospective mates are low in physical attractiveness, learning dealbreakers was associated with less desirability than dealmakers. Furthermore, men were more interested in pursuing casual sex with people of limited physical attractiveness, no matter what other qualities the prospective partner possessed. Compared to women, men were also more willing to form a serious relationship with prospective partners of low physical attractiveness, but only if the prospective partner possessed other desirable qualities (e.g., “This person is kind to strangers.”; “This person dresses well.”). Importantly, women’s lack of interest in physically unattractive people appeared to be insensitive to mating context. This supports past findings that women also value physical attractiveness in their mates (Li and Kenrick 2006) but, unlike men, women’s selectivity led to a lack of interest in forming a relationship with a person of low physical attractiveness, no matter what type of relationship they were seeking.

Chimpanzees: Sex differences in personality were observed, with overall sex differences found for three traits, and males and females showing different trajectories for two further traits over the 10 year period

Sex differences in longitudinal personality stability in chimpanzees. Bruce Rawlings et al. Evolutionary Human Sciences, Volume 22020 , e46, Sep 9 2020. https://www.cambridge.org/core/journals/evolutionary-human-sciences/article/sex-differences-in-longitudinal-personality-stability-in-chimpanzees/6D94DE5CE1BBB5A9E14A21A9A212CFCA

Abstract: Personality factors analogous to the Big Five observed in humans are present in the great apes. However, few studies have examined the long-term stability of great ape personality, particularly using factor-based personality instruments. Here, we assessed overall group, and individual-level, stability of chimpanzee personality by collecting ratings for chimpanzees (N = 50) and comparing them with ratings collected approximately 10 years previously, using the same personality scale. The overall mean scores of three of the six factors differed across the two time points. Sex differences in personality were also observed, with overall sex differences found for three traits, and males and females showing different trajectories for two further traits over the 10 year period. Regardless of sex, rank-order stability analysis revealed strong stability for dominance; individuals who were dominant at the first time point were also dominant 10 years later. The other personality factors exhibited poor to moderate rank-order stability, indicating that individuals were variable in their rank-position consistency over time. As many studies assessing chimpanzee cognition rely on personality data collected several years prior to testing, these data highlight the importance of collecting current personality data when correlating them with cognitive performance.

Republicans Need Not Apply: An Investigation of the American Economic Association Using Voter Registration and Political Contributions

Republicans Need Not Apply: An Investigation of the American Economic Association Using Voter Registration and Political Contributions. Mitchell Langbert. Econ Journal Watch, 17(2). Pages 392–404, Sep 2020. https://econjwatch.org/articles/republicans-need-not-apply-an-investigation-of-the-american-economic-association-using-voter-registration-and-political-contributions

Abstract: The American Economic Association (AEA) is the premier national organization for professional economics in the United States. This paper shows that the AEA is nearly devoid of Republicans, though many Republicans are found among its membership, which remains open to all who pay the membership dues. I find that the political skew increases up the AEA hierarchy. I use voter registration and political contribution data to examine what I call ‘players’—AEA officers, editors, authors, and acknowledgees (that is, those thanked in published acknowledgments). For AEA players, the Democratic:Republican ratio is 13:1 in voter registrations and 81:1 in political contributors. The most influential professional association of economists in the United States is dominated by people on the political left.

Why puzzling? --- In reaction to positive events, studies show a puzzling “mood brightening” effect in individuals with mood disorder symptoms that suggests hyper responsiveness to real-life rewards

Heininga, Vera E., and Peter Kuppens. 2020. “Short Review: Psychopathology and Positive Emotions in Daily Life.” PsyArXiv. October 1. doi:10.31234/osf.io/yse56

Rolf Degen: https://twitter.com/DegenRolf/status/1311659537145888772

Abstract: In this short review, we describe recent trends from research investigating positive affect (PA) in daily life in relation to mood disorders. Aside from notable exceptions (e.g., mania), most mood disorders involve relatively lower levels of PA in daily life, often combined with a larger level of variability in PA. In reaction to positive events, studies show a puzzling “mood brightening” effect in individuals with mood disorder symptoms that suggests hyper responsiveness to real-life rewards. Studies into anhedonia (i.e., lack of, or lower levels of PA) suggest that high-arousal PA and anticipatory PA are potential targets for intervention. Despite PA-focused interventions bear promises of greater therapeutic effectiveness, so far, these promises have not materialized yet.

Ideological differences in attitudes characterized by threat, complexity, morality, political ideology, religious ideology, or harm: The political domain was the only significant predictor of ideological differences

Identifying the domains of ideological similarities and differences in attitudes. Emily Kubin & Mark J. Brandt. Comprehensive Results in Social Psychology, Volume 4, 2020 - Issue 1. Pages 53-77. May 4 2020. https://doi.org/10.1080/23743603.2020.1756242

Rolf Degen's take: https://twitter.com/DegenRolf/status/1311634367517732866

ABSTRACT: Liberals and conservatives disagree, but are there some domains where we are more or less likely to observe ideological differences? To map the types of attitudes where we may be more or less likely to observe ideological differences, we draw on two approaches, the elective affinities approach, which suggests individual differences explains differences between liberals and conservatives, and the divergent content approach, which posits the key distinction between ideologues are their value orientations. The goal of the current research was to explore when and why liberals and conservatives disagree. We tested whether ideological differences are more likely to emerge in attitudes characterized by threat, complexity, morality, political ideology, religious ideology, or harm (as compared to objects not characterized by these domains) using both explicit and implicit measures of 190 attitude objects. While all domains predicted ideological differences, the political domain was the only significant predictor of ideological differences when controlling for the other domains. This study provides insight into which attitudes we are most and least likely to find ideological differences.

KEYWORDS: Ideological differences, attitudes, ideology, threat, complexity

Discussion

We have two key findings. First, we find support for both the elective affinities and divergent content approaches; topics associated with threat, complexity, morality, politics, religion, and harm are also characterized by greater ideological disagreement than topics not associated with these domains. Second, we found that the political domain was the strongest predictor of ideological disagreement.

The current research attempted to map the types of attitudes where we are most and least likely to observe ideological differences. We used two approaches, the elective affinities approach, and the divergent content approach to explore which domains characterize attitudes when there is disagreement between liberals and conservatives. The elective affinities approach, which suggests people prefer views that match their dispositions (Hirsh et al., 2010; Jost et al., 2009), posits that attitude objects characterized by threat (i.e., threat hypothesis) or complexity (i.e., complexity hypothesis) are more likely to be associated with liberal-conservative differences, compared to attitude objects not associated with threat or complexity. The divergent content approach, which suggests that they key difference between groups are underlying values (Haidt & Graham, 2007), posited that attitude objects characterized by morality (i.e., moral hypothesis), politics (i.e., political hypothesis), religion (i.e., religion hypothesis), or harm (i.e., harm hypothesis) are more likely to be associated with liberal-conservative disagreement, compared to attitude objects not associated with morality, politics, religion, or harm.

We tested these hypotheses by estimating ideological differences on implicit (IAT) and explicit (preference and evaluation) measures of attitudes and analyzed the extent to which attitude objects characterized by the proposed domains are more likely to be associated with ideological disagreement. When focusing on each domain individually, we found support for both the elective affinities and divergent content approaches. Results suggested attitudes associated with threat, complexity, morality, politics, religion, and harm were also attitude objects liberals and conservatives tended to disagree on. This was the case for both reaction time (IAT) and self-report (preference or evaluations) measures and for both joint (IAT or preference) and individual judgment (evaluation) contexts. Further, these findings were consistent when controlling for attitude object category, in nearly all cases was not affected by domain rater ideology, and was consistent across robust regression analyses.

Analyses also indicated that the political domain was the most robust predictor of ideological disagreement. When controlling for the other domains, the political domain was the only domain that still predicted the size of ideological differences – suggesting that ideological differences are substantially reduced outside of the political realm. For example, below the midpoint of political ratings the maximum ideological difference is never larger than a small effect (in r, maximum difference on IAT = .20, preference = .22, evaluations = .18) and the means are quite small (in r, mean difference on IAT = .02, preference = .03, evaluations = .03). 10 This is most consistent with the political hypothesis from the divergent content approach (e.g., Brandt & Crawford, in press; Graham et al., 2011).

Primacy of politics?

There are multiple ways to interpret the primacy of politics result. First, this result might suggest that the results supporting the elective affinities approach, as well as the harm, religion, and morality hypotheses of the divergent content approach are not good evidence because domains such as threat and complexity, as well as morality and religion are conflated with political differences. This is consistent with arguments that suggest that links between political ideology, personality, and motivations may be due to content overlap rather than personality or motivational differences per se (Malka et al., 2017). This possibility is represented in the causal structure in Figure S1 (in supplemental materials). 11 All of the domains have the possibility of directly causing ideological differences, but due to shared variance with politics, the political variable is the only significant predictor of ideological differences.

A second possibility is that factors like threat and complexity are the very topics that humans are likely to make into political, moral, or religious issues. When times are threatening or particularly complex, turning issues into political, moral, or religious issues may give people a sense of certainty or a method for interpreting the world that they otherwise would not have. If this is the case, then politics may act more like a mediator of the effects of threat and complexity. This possibility is represented in the causal structure in Figure S2 (in supplemental materials). Notably, in exploratory analyses where we excluded politics as a predictor, threat and complexity were still not significant predictors. Instead either no domain was a significant predictor, or morality was a significant predictor. This hints that morality may also be more proximal than threat and complexity.

The distinction between these two possibilities is theoretically important. The first possibility, represented in Figure S1, would suggest that the elective affinities approach, at least for our research questions, is not viable. The findings that seem to support it are merely due to the confounds between threat, complexity, and politics. The same conclusion could also be drawn from the moral, religious, and harm-related versions of the divergent content approach. However, the second possibility, represented in Figure S2, would suggest that the elective affinities approach, at least for our research questions, is viable. These findings show the disagreements over the political domain is the strongest predictor of ideological disagreement; however, the other domains are potentially still casually potent as precursors to the political domain. Unfortunately, it is not possible to tease apart these possibilities with the current data as the data are cross-sectional. Teasing apart these two possibilities is a necessary task for future research. Ideally, tests might include tracking ideological differences in large numbers across a great diversity of attitudes over time to study changes and stability in ideological differences.

Strength, limitations, and future directions

These findings are just one-step in mapping which attitudes we are most and least likely to anticipate ideological differences. We studied the 190 attitude objects from the AIID study. However, we expect that our findings will likely generalize to other attitudes, especially in the American context. We also would expect a similar pattern of results in other countries with polarized political systems (cf. Pew Research Center, 2017; Vachudova, 2019; Wendler, 2014). We are less certain that these results would replicate in political systems with less polarization and where political differences are, presumably, less important.

In contrast to many studies of ideological differences that focus on differences in one particular attitude, the attitudes in the AIID study cover many topics. These topics range from abstract principles (e.g., realism vs. idealism) to people (e.g., celebrities such as Denzel Washington vs. Tom Cruise) and regions of the world (e.g., Japan vs. the United States). The diversity of attitude objects should make our findings more comparable to the large swath of attitudes in the everyday world. Thus, these findings improve our ability to predict the locations of ideological differences and similarities in untested fields. One challenge with using a large number of attitudes is that not every attitude conforms to the model. As one example, some of the attitudes that scored highly in the political domain nonetheless had low levels of ideological differences. One reason for this is that there were attitudes that were political (e.g., preferences for Bill Clinton vs. Hillary Clinton; evaluations of politicians), but which did not map onto differences between liberals and conservatives. This suggests that more precise predictions can be made by considering the political dimension the attitude maps on to.

Despite the large sample of people and attitudes, and replication across multiple measures, this study also had several limitations. The domains used were based on previously discussed perspectives; however, other domains that we did not include may also play a key role. For example, we did not test the domain of disgust, but attitude objects associated with disgust may be associated with ideological differences, as previous research highlights ideological differences in what is viewed as disgusting (Elad-Strenger et al., 2019; Inbar et al., 2012). Moreover, as previously mentioned, the findings are cross-sectional. Although we discussed the results in causal terms for illustrative purposes, the current data is consistent with a number of different causal models. One way to test this will be to examine if and how ideological differences emerge as an attitude is imbued with different properties. Things that were once not moralized, politicized, threatening, etc., can become linked to our moral or political sensibilities, or be viewed as highly threatening. For example, at one point attitudes about the NFL may have not seemed overly political, however once NFL athletes began kneeling during the national anthem, and President Trump began commenting about these actions (Klein, 2018), the league may have become more politicized. We would expect ideological differences in opinions on the NFL to track this politicization.

Finally, this study is primarily based on self-reports and survey methodology. In the AIID study participants reported which attitude objects they prefer and the extent to which they positively evaluate attitude objects. In Rating Samples 1 and 2, collected many years after the original AIID study, participants self-reported the extent to which they think each domain could explain other people’s disagreement about the attitude objects. Thus, Rating Samples 1 and 2 focus on measuring what people think could cause others to disagree about attitude objects, rather than measuring what actually causes people to disagree about attitude objects. This may limit the validity of the study as participants in Rating Samples 1 and 2 may not be aware of the true factors that drive disagreement over attitude objects.

Furthermore, while implicit associations are assessed, and similar results are found across results, some of our findings are based on self-reports. Tracking ideological disagreement in terms of preference and evaluation can only occur in contexts where individuals are able and willing to report their true political attitudes – meaning further exploration into mapping ideological differences using these self-report methodologies relies on participants willingness to disclose their attitudes.

Behavioral manipulations could also be included in future work, such as having participants actually choose between helping one group (e.g., gay people) vs. another (e.g., straight people). This would help map attitudes where ideological disagreement is (or is not) present to aid in our understanding of the behavioral consequences of differences between liberals and conservatives. However, the consistency in results between the reaction time and self-report measures gives us some confidence that these findings are robust to measurement type.

The current research attempted to map where we are most and least likely to see ideological disagreement. In this paper, we have two key findings. First, we find support for both the elective affinities and divergent content approaches; topics associated with threat, complexity, morality, politics, religion, and harm are also characterized by greater ideological disagreement than topics not associated with these domains. Second, we found that the political domain was the strongest predictor of ideological disagreement. These findings provide evidence for a systematic explanation for when and why liberals and conservatives disagree, and can aid in predicting whether future events will be heavily contested or will be similarly perceived by liberals and conservatives.

The major genetic risk factor for severe COVID-19 is inherited from Neanderthals

The major genetic risk factor for severe COVID-19 is inherited from Neanderthals. Hugo Zeberg & Svante Pääbo. Nature, Sep 30 2020. https://www.nature.com/articles/s41586-020-2818-3

Abstract: A recent genetic association study1 identified a gene cluster on chromosome 3 as a risk locus for respiratory failure upon SARS-CoV-2 infection. A new study2 comprising 3,199 hospitalized COVID-19 patients and controls finds that this is the major genetic risk factor for severe SARS-CoV-2 infection and hospitalization (COVID-19 Host Genetics Initiative). Here, we show that the risk is conferred by a genomic segment of ~50 kb that is inherited from Neanderthals and is carried by ~50% of people in South Asia and ~16% of people in Europe today.

Popular version: https://www.cathlabdigest.com/content/neandertal-gene-variant-increases-risk-severe-covid-19