They found no systematic effect of stress on prosocial behaviours

Effect of mood and worker incentives on workplace productivity. Decio Coviello, Erika Deserranno, Nicola Persico, Paola Sapienza. The Journal of Law, Economics, and Organization, ewac017, September 26 2022. https://doi.org/10.1093/jleo/ewac017

Abstract: We study the causal effect of mood on the productivity of call-center workers. Mood is measured through an online “mood questionnaire” which the workers are encouraged to fill out daily. We find that better mood actually decreases worker productivity for workers whose compensation is largely fixed. The negative effect of mood is attenuated for workers whose compensation is based on performance (high-powered incentives). This finding holds both at a correlational level and in two IV settings, where mood is instrumented for by weather or, alternatively, by whether the local professional sports team played/won the day before. We rule out a number of threats to the exclusion restrictions, and discuss the mechanisms that could generate our findings

JEL: J24, J28, M52, C26

Sleeping poorly is robustly associated with a tendency to engage in spontaneous waking thought

Sleeping poorly is robustly associated with a tendency to engage in spontaneous waking thought. Ana Lucía Cárdenas-Egúsquiza, Dorthe Berntsen. Consciousness and Cognition, Volume 105, October 2022, 103401. https://doi.org/10.1016/j.concog.2022.103401

Highlights
•    A comprehensive study on the relationship between self-reported sleep and spontaneous thought tendencies.
•    A wide variety of sleep and spontaneous thoughts measures were included.
•    Sleep predicted spontaneous thoughts tendencies, controlling for trait negative affect.
•    Sleep did not predict the frequency of positive-constructive spontaneous thought.
•    Findings demonstrate the unique role of sleep in relation to spontaneous cognition.

Abstract: We spend approximately-one third of our lives sleeping, and spontaneous thoughts dominate around 20–50% of our waking life, but little is known about the relation between the two. Studies examining this relationship measured only certain aspects of sleep and certain forms of spontaneous thought, which is problematic given the heterogeneity of both conceptions. The scarce literature suggests that disturbed sleep and the frequency of spontaneous waking thoughts are associated, however this could be caused by shared variance with negative affect. We report a comprehensive survey study with a large range of self-reported sleep and spontaneous thought measures (N = 236), showing that poorer sleep quality, more daytime-sleepiness, and more insomnia symptoms, consistently predicted higher tendencies to engage in disruptive spontaneous thoughts, independently of trait negative affect, age and gender. Contrarily, only daytime sleepiness predicted positive-constructive daydreaming. Findings underscore the role of sleep for spontaneous cognition tendencies.

4. Discussion

We examined associations between different self-reported aspects of sleep, a variety of spontaneous thoughts tendencies and trait affect in a comprehensive survey study. The findings generally agreed with our predictions. First, subjective measures of disturbed sleep were consistently associated with higher tendencies to engage in disruptive spontaneous thoughts, but not positive constructive daydreaming. Second, subjective measures of disturbed sleep were associated with higher tendencies toward negative affect and lower tendencies to positive affect. Third, higher tendencies to engage in disruptive spontaneous thoughts were related to higher trait negative affect, whereas a tendency toward positive constructive daydreaming was related only to more positive affect. Fourth, subjective measures of disturbed sleep were significant predictors of disruptive, and, especially, poor attention-related spontaneous thoughts, above and beyond negative affect tendencies, age and gender. The emotionally valenced daydreaming styles showed different patterns: a tendency toward positive constructive daydreaming was predicted only by subjective daytime sleepiness. A tendency toward guilt-fear of failure daydreaming was not predicted by any of the subjective sleep measures, but it was predicted by higher negative affect tendencies.

The study adds to the literature by showing that the relationship between self-reported disturbed sleep and the tendency to engage in disruptive spontaneous thoughts is not driven solely by negative affect. Self-reported sleep quality, daytime sleepiness, and insomnia symptoms predicted a tendency to engage in various forms of spontaneous thoughts, beyond negative affect tendencies, age and gender. This suggests other mechanisms behind the relationship between subjective sleep and spontaneous thought tendencies, besides shared associations with negative affect. First, self-reported poor sleep quality (Nebes, Buysse, Halligan, Houck, & Monk, 2009), insomnia (Liu et al., 2014) and daytime sleepiness (Anderson, Storfer-Isser, Taylor, Rosen, & Redline, 2009) have been related to reduced executive cognitive control. Impaired executive control in people suffering from disturbed sleep could reduce their ability to prevent the mind from wandering. This is consistent with the executive-failure account of mind wandering, which proposes that mind wandering episodes occur due to failures in the executive control system (McVay & Kane, 2010). Second, poor sleep quality, insomnia symptoms and daytime sleepiness have been associated with disrupted connectivity of the resting state, default mode network (DMN, Killgore., 2015, Nie et al., 2015, Tashjian et al., 2018). Poor sleep has also been associated with altered connectivity of attentional networks (Tomasi et al., 2009). Speculatively, both changes may be associated with an increased tendency to engage in mind wandering (e.g., Christoff et al., 2009, Poerio et al., 2017, Van Calster et al., 2017). Third, poor sleep quality increases sleep pressure (i.e. the increasing need for sleep per time awake) and this, in turn, increases the occurrence of local sleep-like activity in specific brain areas and networks involved in specific tasks (Cajochen et al., 1995, Muto et al., 2016). Local sleep-like activity in task-specific brain areas has been proposed as a neurophysiological marker of mind wandering experiences (Andrillon et al., 2019, Jubera-Garcia et al., 2021). Another speculative possibility is that an increase in the tendency for experiencing spontaneous thoughts may be a compensatory or restorative response to a lack of good sleep, equivalent to REM-sleep compensation (Carciofo et al., 2014b, Scullin and Gao, 2018). Finally, pressing current concerns, such as financial or social problems or recent stressful events, may influence sleep quality and/or cause insomnia (Van Laethem et al., 2015) and at the same time increase the tendency to engage in spontaneous thought when being awake (Klinger, 2009). Further research is needed to clarify whether and how these mechanisms interact with one another to regulate the tendency for experiencing spontaneous thoughts.

The tendency to engage in positive constructive daydreaming was not associated with, nor predicted by, any of the disturbed sleep measures, except for daytime sleepiness. This is consistent with previous research that failed to find an association between sleep quality and problem-solving daydreaming (Carciofo et al., 2014b, Denis and Poerio, 2017); between insomnia and positive constructive daydreaming (Starker and Hasenfeld, 1976, Starker, 1985) and between a tendency towards eveningness and problem-solving daydreaming (Carciofo et al., 2014b). These findings agree with the view that positive constructive daydreaming is a distinct form of spontaneous thought. It may serve as a source of problem solving, future planning, creativity and fantasy (Antrobus et al., 1966, Huba et al., 1977, Singer, 1966), as well as being related to compassion, simulating another person’s perspective and deriving meaning from events and experiences (Immordino-Yang, Christodoulou, & Singh, 2012). Therefore, and as suggested by Cárdenas-Egúsquiza and Berntsen (2022), positive constructive daydreaming may differ from disruptive spontaneous thoughts by at least two specific features. First, people who report higher tendencies to engage in positive constructive daydreaming also report higher tendencies toward positive affect, showing that this type of spontaneous thought is related to positively valenced emotions (Carciofo et al., 2014b), whereas most other forms of spontaneous thought are associated with negative affectivity (e.g., Killingsworth & Gilbert, 2010). Second, positive constructive daydreams may more often be initiated intentionally (Seli et al., 2016, Seli et al., 2017). People may frequently engage in positive daydreaming, such as planning an activity or solving a problem, in a deliberative fashion, which would then require executive functions to decouple from a current task or activity in order to sustain the daydream (Smallwood, 2013, Smallwood and Schooler, 2006).

In this line, one would expect people reporting disturbed sleep to show lower tendencies to engage in positive constructive daydreaming, due to reduced executive functioning. This is consistent with Carciofo et al. (2014b) who found more subjective daytime sleepiness related to less problem solving daydreaming. In the present study, however, we unexpectedly found more daytime sleepiness to be associated with higher tendencies to engage in positive constructive daydreaming. This discrepancy may reflect that the measure used in the present study assessed a broader concept of positive constructive daydreaming (i.e. fantasy, imagination, vivid imagery; McMillan et al., 2013) than problem solving and future planning as examined by Carciofo et al. (2014b).

The raw correlations showed consistent associations between self-reported measures of disturbed sleep and tendencies to engage in guilt-fear of failure daydreaming. However, disturbed sleep measures did not predict guilt-fear of failure daydreaming when controlling for negative affect tendencies in the regression analyses. This suggests that the association between self-reported insomnia symptoms and guilt-fear of failure daydreaming found in previous research (Starker, 1985, Starker and Hasenfeld, 1976) might have been driven by negative affectivity and not by insomnia symptomatology itself. This would be consistent with the maladaptive and negatively valenced nature of the guilt and fear-of-failure daydreaming style, which involves depressing, frightening and panicking daydreams related to fearing and failing responsibilities, failing loved ones, aggressing others and lying (Antrobus et al., 1966, Huba et al., 1977, McMillan et al., 2013, Singer, 1966).

Finally, younger age appeared to be a robust predictor of higher tendencies to engage in all the spontaneous thoughts measured in this study, except for involuntary mental time travel. This supports prior observations of decreased prevalence of mind wandering and daydreaming in older adults (Berntsen et al., 2015), and a less clear age-related decline for involuntary remembering (Berntsen et al., 2017, Maillet and Schacter, 2016).

The present study holds limitations. First, the cross-sectional and self-report nature of our data prevents reasoning about causality as well as generalizability to experimental studies. Here we used subjective measures of sleep, spontaneous thoughts and affectivity. We acknowledge that trait and state-level measures capture different aspects of the same phenomenon. However, we note that our results agree with previous survey and experimental studies measuring both trait and state-level sleep and spontaneous cognition (Cárdenas-Egúsquiza & Berntsen, 2022). Nonetheless, a bidirectional relationship in which the tendency to engage in spontaneous thoughts predicts the quality and duration of sleep is a possibility that should be further explored (Marcusson-Clavertz et al., 2019). Second, the influence of sleep duration (considered an aspect of sleep quality, Buysse et al., 1989, Kline, 2013) on the frequency of spontaneous thoughts was not examined in depth in the present study (but see the Supplementary Material Table S1 on correlations with sleep duration) and previous research has revealed inconsistent results (Robison et al., 2020, Walker and Trick, 2018). Third, we only applied the widely used PANAS to assess trait negative affectivity and its relation to spontaneous thoughts and sleep outcomes. However, other measures strongly related to negative affect, such as trait neuroticism, have been associated with more mind wandering, poorer sleep quality and a tendency towards eveningness (Carciofo, 2020, Carciofo and Jiang, 2021, Carciofo et al., 2016). Lastly, we acknowledge that the data were collected in November 2020, when lockdown restrictions to reduce the spread of the Covid-19 virus were still in place in several states in the United States of America, which may have influenced the findings (Leone et al., 2020, Simor et al., 2021). However, most of our results are consistent with previous research performed before the Covid-19 pandemic, suggesting that the relationships between subjective sleep outcomes and the tendency to engage in spontaneous thoughts are not contextual and seem to remain even during unusual situations.

Aversion to Low-Probability Gains, even with no possibility of money loss

Opportunity Neglect: An Aversion to Low-Probability Gains. Emily Prinsloo et al. Psychological Science, Sep 26 2022. https://doi.org/10.1177/09567976221091801

Abstract: Seven preregistered studies (N = 2,890, adult participants) conducted in the field, in the lab, and online documented opportunity neglect: a tendency to reject opportunities with low probability of success even when they come with little or no objective cost (e.g., time, money, reputation). Participants rejected a low-probability opportunity in an everyday context (Study 1). Participants also rejected incentive-compatible gambles with positive expected value—for both goods (Study 2) and money (Studies 3–7)—even with no possibility of monetary loss and nontrivial rewards (e.g., a 1% chance at $99). Participants rejected low-probability opportunities more frequently than high-probability opportunities with equal expected value (Study 3). Although taking some real-life opportunities comes with costs, we show that people are even willing to incur costs to opt out of low-probability opportunities (Study 4). Opportunity neglect can be mitigated by highlighting that rejecting an opportunity is equivalent to choosing a zero probability of success (Studies 6–7).

Atheism is as ancient and natural as belief in gods

Atheism: A New Evolutionary Perspective on Non-Belief. Thomas J. Coleman, Kyle J. Messick, Valerie van Mulukom. Oct 2022. Chapter in The Routledge Handbook of Evolutionary Approaches to Religion. https://www.taylorfrancis.com/chapters/edit/10.4324/b23047-12/atheism-thomas-coleman-kyle-messick-valerie-van-mulukom

Abstract: In this chapter, we argue that evolutionary perspectives on atheism have been constrained by a methodological commitment that places atheists at the low end of a religiosity continuum and/or assumes they are psychologically atypical because of their rejection of religious beliefs, if truly rejecting religious beliefs is even possible. In contrast to those positions, we explore the possibility that, like religious belief, atheistic belief could be defined in “positive” terms, linked to evolved psychological mechanisms, and used to produce individual evolutionarily adaptive outcomes. Thus, we review the methodological considerations pertinent to the development of this position and used these to frame the influx of scientific research on atheism conducted over the past several years.

Market-integrated participants display universalism in moral decision-making, & non-market participants make more moral decisions towards co-villagers

Market Participation and Moral Decision-Making: Experimental Evidence from Greenland. Gustav Agneman, Esther Chevrot-Bianco. The Economic Journal, ueac069, September 23 2022. https://doi.org/10.1093/ej/ueac069

Abstract: The relationship between market participation and moral values is the object of a long-lasting debate in economics, yet field evidence is mainly based on cross-cultural studies. We conduct rule-breaking experiments in 13 villages across Greenland (N=543), where stark contrasts in market participation within villages allow us to examine the relationship between market participation and moral decision-making holding village-level factors constant. First, we document a robust positive association between market participation and moral behaviour towards anonymous others. Second, market-integrated participants display universalism in moral decision-making, whereas non-market participants make more moral decisions towards co-villagers. A battery of robustness tests confirms that the behavioural differences between market and non-market participants are not driven by socioeconomic variables, childhood background, cultural identities, kinship structure, global connectedness, and exposure to religious and political institutions.

JEL C91 - Laboratory, Individual BehaviorD01 - Microeconomic Behavior: Underlying PrinciplesD62 - Externalities

Do Children Cause the Cognitive Stimulation They Receive? Modelling the Direction of Causality

Oginni, Olakunle, and Sophie von Stumm. 2022. “Do Children Cause the Cognitive Stimulation They Receive? Modelling the Direction of Causality.” PsyArXiv. October 8. psyarxiv.com/pqf78

Abstract

We tested the directionality of associations between children’s early-life cognitive development and the cognitive stimulation that they received from their parents. Our sample included up to 15,314 children from the Twins Early Development Study (TEDS), who were born between 1994 and 1996 and assessed at age 3 and 4 years on cognitive development and cognitive stimulation, including singing rhymes, reading books, and playing games.

Across a series of genetically informative models, we found consistent, bidirectional causal influences from cognitive development at age 3 to cognitive stimulation at age 4, and from cognitive stimulation at age 3 to cognitive development at age 4. The prospective causal paths in both directions accounted for a third and up to half of the constructs’ phenotypic correlations. Our findings emphasize the active role that children play in constructing their learning experiences, and challenge the idea that children are passive recipients of environmental inputs.

Discussion

Twin studies can be used to strengthen causal inferences for observed associations between two constructs by controlling for their shared genetic and environmental influences (McAdams et al., 2021). Specifically, twin studies can address whether associations between a putatively environmental exposure and developmental differences in a phenotype remain significant after accounting for the confounding effects of shared etiology (i.e., common causes; McAdams et al., 2021). Recent years have seen an explosion of novel modelling approaches that extend the classical twin design, which enable causal inferences but are yet to be systematically applied in psychological research (Eberli et al., 2019; McAdams et al., 2021). Here, we fitted direction-of-causality (DoC) models (Heath, 1993), Mendelian Randomization (MR) extensions of the DoC model (Minică et al., 2018), and cross-lagged twin models (Burt et al., 2005) to investigate if children’s cognitive stimulation causes their cognitive development or vice versa at age 3 and 4 years.

We found prospective causal associations between children’s cognitive development and their cognitive stimulation that were bidirectional. Thus, contemporaneous mechanisms drive the causal influences between cognitive ability and stimulation: Children benefit from experiencing cognitively stimulating environments, and at the same time their cognitive development evokes the cognitive stimulation that their parents provide. Our findings align with a growing body of evidence documenting that children are not passive recipients of environmental inputs but select, modify, and create experiences that are correlated with their genetic proclivities (Bronfenbrenner & Morris, 2006; Wertz et al., 2019).

The prospective, bidirectional causal influences between cognitive development and cognitive stimulation were significant, accounting for between a third to nearly half of their phenotypic correlations across time. Thus, a substantial proportion of the phenotypic associations between cognitive development and cognitive stimulation can be attributed to bidirectional causal effects, while shared etiology or common causes – in particular, the shared environment – accounted for the remainder of the correlations. Finding that common causes and bidirectional causal effects jointly explain the associations between cognitive development and cognitive stimulation is key for developing realistic expectations for the magnitude of the effects that early-life interventions can possibly achieve (von Stumm, 2022).

We also showed that children’s differences in cognitive development and stimulation are largely due to shared environmental influences (56%-74%), followed by additive genetic influences (24%-40%). A similar pattern emerged for the etiologies of the associations between cognitive development and stimulation, which were again mainly due to shared environmental (76%-83%) and then additive genetic influences (16%-20%). Non-shared environmental influences on cognitive development and cognitive stimulation were negligible. While this study is to our knowledge the first to estimate the heritability of cognitive stimulation and its association with cognitive development, our findings confirm that all traits are heritable, including putatively environmental measures that are genetically influenced (Krapohl et al., 2017; Plomin, 1995; Polderman et al., 2015).

Limitations

Notwithstanding this study’s many strengths, including the analysis of twin and genomic data, large sample sizes, and repeated assessments of the core constructs using state-of-the-art methods, it is not without limitations. First, cognitive stimulation was assessed using seven parent-reported items, but a multi-informant approach (i.e., naturalistic home observations) with a greater number of observed variables would have improved the measures’ validity. Second, data on cognitive stimulation were only collected at the twins ages 3 and 4 years, which made it impossible to test for meaningful changes in the direction of causality over the longer course of childhood. Third, the association between the PGS for years spent in education (Lee et al., 2018) and cognitive development was small, which is indicative of weak instrument biases that can lead to overestimation of causal effects (Burgess & Thompson, 2011). In addition, cognitive development and cognitive stimulation did not have a sufficiently differentiated genetic architecture to meet the assumptions of DoC models (Health, 1993; van Bergen et al., 2018). As a result, our preregistered analysis strategy was not viable, and we fitted cross-lagged twin models instead that require longitudinal data.

On average, people tend to overstate the improvement in their well-being over time and to understate their past happiness

Feeling Good Is Feeling Better. Alberto Prati and Claudia Senik. Psychological Science, Oct 7 2022. https://doi.org/10.1177/09567976221096158

Abstract: Can people remember their past happiness? We analyzed data from four longitudinal surveys from the United States, France, the United Kingdom, and Germany spanning from the 1970s until the present, in which more than 60,000 adults were asked questions about their current and past life satisfaction. We uncovered systematic biases in recalled happiness: On average, people tended to overstate the improvement in their well-being over time and to understate their past happiness. But this aggregate figure hides a deep asymmetry: Whereas happy people recall the evolution of their life to be better than it was, unhappy ones tend to exaggerate their life’s negative evolution. It thus seems that feeling happy today implies feeling better than yesterday. This recall structure has implications for motivated memory and learning and could explain why happy people are more optimistic, perceive risks to be lower, and are more open to new experiences.

The Equality Paradox: Gender Equality Intensifies Male Advantages in Adolescent Subjective Well-Being

The Equality Paradox: Gender Equality Intensifies Male Advantages in Adolescent Subjective Well-Being. Jiesi Guo et al. Personality and Social Psychology Bulletin, October 7, 2022. https://doi.org/10.1177/01461672221125619

Abstract: Individuals’ subjective well-being (SWB) is an important marker of development and social progress. As psychological health issues often begin during adolescence, understanding the factors that enhance SWB among adolescents is critical to devising preventive interventions. However, little is known about how institutional contexts contribute to adolescent SWB. Using Programme for International Student Assessment (PISA) 2015 and 2018 data from 78 countries (N = 941,475), we find that gender gaps in adolescents’ SWB (life satisfaction, positive and negative affect) are larger in more gender-equal countries. Results paradoxically indicated that gender equality enhances boys’ but not girls’ SWB, suggesting that greater gender equality may facilitate social comparisons across genders. This may lead to an increased awareness of discrimination against females and consequently lower girls’ SWB, diluting the overall benefits of gender equality. These findings underscore the need for researchers and policy-makers to better understand macro-level factors, beyond objective gender equality, that support girls’ SWB.

Social salience of self-control (tight) vs-self-indulgence (loose) orientations, English books, XX century: The trend of self-control displays a steady increase throughout, self-indulgence increases from the late 70s-early 80s

The self-control vs. self-indulgence dilemma: A culturomic analysis of 20th century trends. Alberto Acerbi, Pier Luigi Sacco. Journal of Behavioral and Experimental Economics, October 6 2022, 101946. https://doi.org/10.1016/j.socec.2022.101946

Highlights

• We study the long-term dynamics of self-control vs. self-indulgence

• We adopt a culturomic approach analyzing the Google Books English corpus

• Self-indulgence shows a trend reversal around the 80s

• The analysis clearly tracks the onset of the consumerist revolution

• Our results are robust to choice of high-frequency words

Abstract: Within the conceptual framework of the Tightness-Looseness paradigm, we study the dynamics of the social salience of self-control (tight) vs-self-indulgence (loose) orientations across the 20th century on the basis of the English Google Books corpus, by means of the construction of specific lexica of which we track their relative frequency. We find that whereas the trend of self-control displays a steady increase throughout, that of self-indulgence is U-shaped, so that following a decline along the most part of the century, starting from the late 70s-early 80s we observe a reversal of the trend that signals an increasing salience of self-indulgence. Such result seems to reflect the consumerist turn that has characterized the post-industrial cycle from the 80s onwards. The coexistence of growing trends for mutually antagonizing orientations calls for further analysis of their social interplay. We also perform a parallel analysis on semantically related lexica that confirm the robustness of our findings.

Keywords: Self-controlself-indulgenceTightness-Loosenessculturomicsconsumerism

JEL: B52C89Z13

Excessive or deficient levels of neuronal inhibition relative to neuronal excitation may account for disorders of sexual desire, arousal and orgasm

Komisaruk BR, Rodriguez del Cerro MC. Orgasm and Related Disorders Depend on Neural Inhibition Combined With Neural Excitation. Sexual Medicine Reviews Volume 10, Issue 4, October 2022, Pages 481-492. https://doi.org/10.1016/j.sxmr.2022.07.001

Abstract

Introduction: Prevalent models of sexual desire, arousal and orgasm postulate that they result from an excitatory process, whereas disorders of sexual desire, arousal and orgasm result from an inhibitory process based on psychosocial, pharmacological, medical, and other factors. But neuronal excitation and active neuronal inhibition normally interact at variable intensities, concurrently and continuously. We propose herein that in conjunction with neuronal excitation, neuronal inhibition enables the generation of the intense, non-aversive pleasure of orgasm. When this interaction breaks down, pathology can result, as in disorders of sexual desire, arousal, and orgasm, and in anhedonia and pain. For perspective, we review some fundamental behavioral and (neuro-) physiological functions of neuronal excitation and inhibition in normal and pathological processes.

Objectives: To review evidence that the variable balance between neuronal excitation and active neuronal inhibition at different intensities can account for orgasm and its disorders.

Methods: We selected studies from searches on PubMed, Google Scholar, Dialnet, and SciELO for terms including orgasm, neuronal development, Wallerian degeneration, prenatal stress, parental behavior, sensorimotor, neuronal excitation, neuronal inhibition, sensory deprivation, anhedonia, orgasmic disorder, hypoactive sexual desire disorder, persistent genital arousal disorder, sexual pain.

Results: We provide evidence that the intensity of neuronal inhibition dynamically covaries concurrently with the intensity of neuronal excitation. Differences in these relative intensities can facilitate the understanding of orgasm and disorders of orgasm.

Conclusion: Neuronal excitation and neuronal inhibition are normal, continuously active processes of the nervous system that are necessary for survival of neurons and the organism. The ability of genital sensory stimulation to induce concurrent neuronal inhibition enables the stimulation to attain the pleasurable, non-aversive, high intensity of excitation characteristic of orgasm. Excessive or deficient levels of neuronal inhibition relative to neuronal excitation may account for disorders of sexual desire, arousal and orgasm.

Key Words: OrgasmExcitationInhibitionHSDDFODPGADAnhedoniaPainPrenatal stressAnalgesia

Signs of a Flynn effect in rodents in the last century? Secular differentiation of the manifold of general cognitive ability in laboratory mice (Mus musculus) and Norwegian rats (Rattus norvegicus)

Signs of a Flynn effect in rodents? Secular differentiation of the manifold of general cognitive ability in laboratory mice (Mus musculus) and Norwegian rats (Rattus norvegicus) over a century—Results from two cross-temporal meta-analyses. Michael A. Woodley of Menie, Mateo Peñaherrera-Aguirre, Matthew A. Sarraf. Intelligence, Volume 95, November–December 2022, 101700. https://doi.org/10.1016/j.intell.2022.101700

Highlights
•    Cross-temporal meta-analysis of GCA variance across 100 years in rat and mice populations.
•    Evidence of GCA variance decline (differentiation) found for both.
•    Suggestive of a Flynn effect, as this is associated with differentiation.
•    Laboratory studies can directly test for this in future research.

Abstract: Substantial improvements in factors such as microbiological quality have been noted in laboratory rodent (mouse [Mus musculus] and rat [Rattus norvegicus]) populations over the last 140 years, since domestication of laboratory strains started. These environmental improvements may have caused Flynn effect-like cognitive changes to occur in these populations, perhaps if these improvements enhanced cognitive plasticity and, consequently, learning potential. While lack of relevant data precludes cross-temporal comparison of cognitive performance means of laboratory rodent populations, it is possible to estimate changes in the proportion of cognitive performance variance attributable to general cognitive ability (GCA) over time. This “differentiation effect” has been found to occur along with the Flynn effect in human populations, suggesting that environmental factors, possibly mediated by their effects on life history speed, may weaken the manifold of GCA across time, allowing for greater cultivation of specialized abilities. Meta-analysis of the literature on mouse and rat cognition yielded 25 mouse studies from which 28 GCA effect sizes could be estimated, and 10 rat studies from which 11 effect sizes could be estimated. Cross-temporal meta-analysis yielded evidence of significant “differentiation effects” spanning approximately a century in both mice and rats, which were independent of age, sex, factor estimation technique, and task number in the case of the mice, and both factor estimation technique and task number in the case of the rats. These trends were also independent of the random effect of strain in both cases. While this is suggestive of the presence of the Flynn effect in captive populations of non-human animals, there are still factors that might be confounding these results. This meta-analysis should be followed up with experimental investigation.

The Dark Triad (psychopathy, Machiavellianism and narcissism) in adults: Only psychopathy and Machiavellianism were related to adult offending

How well do the Dark Triad characteristics explain individual differences in offending in a representative non-clinical adult sample? Wim Hardyns et al. Current Research in Behavioral Sciences, October 5 2022, 100084. https://doi.org/10.1016/j.crbeha.2022.100084

Highlights
•    Psychopathy, Machiavellianism and narcissism make up the Dark Triad of personality
•    These Dark Triad traits were proven to be related to numerous antisocial behaviors
•    Such research on the Dark Triad has mainly focused on adolescent (online) samples
•    We tested the effect of these traits on offending in a representative adult sample
•    Of the three, only psychopathy and Machiavellianism were related to adult offending

Abstract: The present study investigates to what extent the three key concepts from the Dark Triad Theory can explain individual differences in adult offending. Data were collected through a cross-sectional survey amongst a representative sample of 1587 adults, living in Ghent, Belgium (Mage = 48.06, 51.4% female). Negative binomial regression analyses are run and show that Machiavellianism and psychopathy have strong independent effects on adult offending, independent of age, sex and immigrant background.

4. Discussion

The main objective of this study was to examine to what extent the key dimensions of the Dark Triad Theory are able to explain individual differences in self-reported adult offending. This study adds to existing and still scarce literature by examining this association in a representative non-clinical sample of adults, whereas previous research on the Dark Triad personality traits has primarily focused on adolescent (online) samples.

Psychopathy and Machiavellianism had substantial net effects on adult offending, which is consistent with our hypothesis and previous research with adolescent samples (e.g., Flexon et al., 2016; Lyons & Jonason, 2015; Wright et al., 2016). However, in contrast to our hypothesis and previous research (e.g., Blinkhorn et al., 2018), narcissism was not significantly related to self-reported adult offending. This lack of association could possibly be explained by Bushman and Baumeister's (1998) threatened egotism hypothesis, which posits that individuals who are high on narcissism are prone to react in a violent or aggressive manner as a defense mechanism when faced with challenges to their self-esteem. Several studies have found evidence for this hypothesis (e.g., Baumeister, Bushman, & Campbell, 2000; Lambe et al., 2016; Twenge & Campbell, 2003). Our data did not allow to distinguish proactive offending from reactive offending (such as an ego threat), thus we cannot fully explain this lack of association. Future research could examine this further by including measures of both proactive and reactive offending behaviors.

Next to discussing the net effects of the Dark Triad traits, it is also worth mentioning that the effects of age and immigrant background on offending behavior were in line with previous research (e.g., Junger-Tas et al., 2009; Rocque et al., 2015). However, our third control variable sex did not have the expected effect on offending. Research has repeatedly shown that males are more prone to offending than females (e.g., DeLisi & Vaughn, 2016), but in our study this effect of sex is not substantial. One possible explanation for this is that the effect of sociodemographic variables such as sex may weaken when other variables, such as personal attitudes, values or personality traits, are taken into account when analyzing offending behavior (Ivert et al., 2018). In our study, the effects of the Dark Triad personality traits could have weakened the effect of sex on adult offending, but further research is required to support this claim.

5. Limitations and future directions

Several limitations must be taken into account. First, the cross-sectional nature of the study makes it impossible to draw causal conclusions and therefore limits the ability to discuss clear causal relationships of our findings. From a developmental point of view, a panel study should be implemented to assess the temporal order of the concepts in our model and to examine whether changes in the presence of the Dark Triad personality traits are indeed associated with changes in offending behavior.

A second limitation concerns the self-report nature of the measures of each construct. This raises problems with memory recall in regard to the questions on offending, the willingness to report about sensitive topics like offending, and social desirability bias, especially considering the Dark Triad traits are characterized by tendencies towards self-promotion (Paulhus & Williams, 2002). However, previous research has demonstrated that self-report measurements of the Dark Triad can be quite accurate (Jonason & Webster, 2010), and a recent study by Kowalski et al. (2018) found that only narcissism is associated with social desirability, which can be an explanation for the non-effect of narcissism in this study. We tried to limit the confounding effects of the social desirability bias by shielding the questions relating to offending behavior and Dark Triad personality traits from the interviewers. Future research could also assess the validity of self-reporting occurrences of offending behavior through the use of factorial designs (randomized vignette studies).

Third, in our operationalization of the Dark Triad personality traits, we used a concise measure (Dirty Dozen; Jonason & Webster, 2010). While there is considerable support for the adequacy of the psychometric properties of this scale such as internal consistency, factor structure and test-retest validity (e.g., Chiorri, Garofalo, & Velotti, 2019; Jonason et al., 2013; Jonason & Luévano, 2013; Jonason & McCain, 2012; Jonason & Webster, 2010; Jones & Paulhus, 2014), there are some concerns regarding the brevity of the instrument in relation to full-length measures of the Dark Triad traits³. Some scholars have proposed that this short measure may fail to capture some aspects of psychopathy and narcissism (e.g., Maples, Lamkin, & Miller, 2014). However, the structure of the Dirty Dozen questionnaire appears to be stable across different cultural contexts and populations and seems to provide a reasonable tradeoff between efficiency and accuracy (Jonason & Luévano, 2013; Rogoza et al., 2020).

Lastly, the adults offending scale is based on four items referring to four types of offending behaviors. Our choice was guided by (1) general applicability towards a community sample and (2) high prevalence offences.⁴ Future research on the association between the Dark Triad traits and offending behavior could incorporate measures of more specific types of offending behaviors.

Despite these limitations, our findings show that the Dark Triad Theory can be applied to explain individual differences in adult offending and as such, the theory could be integrated in contemporary theories of antisocial behavior. Future research could examine which mechanisms lie underneath this relationship between the Dark Triad traits and self-reported offending, by integrating the findings of this study with for example theory on the role of self-control (Flexon et al., 2016; Gottfredson & Hirschi, 2019; Vazsonyi et al., 2017; Wright et al., 2017) and strains (Agnew et al., 2002; Lee & Kim, 2022) in criminal behavior, or the theory of cumulated disadvantage (Sampson & Laub, 1997). Furthermore, given the moderate to large heritability of the Dark Triad traits (Kavish & Boutwell, 2022; Vernon et al., 2008), future research could explore the role of genetic confounding in the association between these three dark personality traits and offending behavior. This strategy of theoretical elaboration could lead to a more thorough understanding of the individual factors that play a role in offending behaviors.

Lottery playing has an entertainment function, in that people can improve their mood by spending a small amount of money

What we bet on is not only tangible money, but also good mood. Hui-Fang Guo et al. Cognition and Emotion, Oct 3 2022. https://doi.org/10.1080/02699931.2022.2128064

A surprisingly large number of lottery prizes go unclaimed every year. This leads us to suspect that what people bet on is not only money, but also good mood. We conducted three studies to explain, from an emotional perspective, why people play lottery games. We first conducted two survey studies to assess mood state reported by online (Study 1a) and offline lottery buyers (Study 1b) at different stages of lottery play. The results revealed that participants’ highest mood appeared before knowing whether they had won. In Study 2, we manipulated the means of reward (lottery tickets vs. cash) and compared participants’ mood changes at different stages of a rewards game in the laboratory. We found the following: first, lottery group participants were generally in a better mood; second, 42% of lottery group participants did not come to the laboratory to collect scratch cards; and third, lottery group participants took more time to return to the laboratory to check their tickets than participants in the cash group. In Study 3, we examined whether priming good or bad mood could influence participants’ preferences for cash versus lottery tickets. The results revealed that participants who were primed for poor mood had a higher preference for lottery tickets compared with their good mood counterparts. These findings suggest that what our participants sought in lottery play was not only money, but improved mood.

Keywords: Lottery playmoodextremely low probabilityweighting function of prospect theory

In the 60s-80s, women were less likely to be selected as Academies members than men with similar records (in Psychology, Mathematics and Economics); by the 1990s, 50-50; since 2000, women are 3-15 times more likely to be selected as members

Gender Gaps at the Academies. David Card, Stefano DellaVigna, Patricia Funk & Nagore Iriberri. NBER Working Paper 30510, September 2022. DOI 10.3386/w30510

Historically, a large majority of the newly elected members of the National Academy of Science (NAS) and the American Academy of Arts and Science (AAAS) were men. Within the past two decades, however, that situation has changed, and in the last 3 years women made up about 40 percent of the new members in both academies. We build lists of active scholars from publications in the top journals in three fields – Psychology, Mathematics and Economics – and develop a series of models to compare changes in the probability of selection of women as members of the NAS and AAAS from the 1960s to today, controlling for publications and citations. In the early years of our sample, women were less likely to be selected as members than men with similar records. By the 1990s, the selection process at both academies was approximately gender-neutral, conditional on publications and citations. In the past 20 years, however, a positive preference for female members has emerged and strengthened in all three fields. Currently, women are 3-15 times more likely to be selected as members of the AAAS and NAS than men with similar publication and citation records.

 

"Minority-distinct" name in resumes: Discrimination in some "unexpected" countries aren't that surprising to those who travel, but that runs counter the usual narrative

Do Some Countries Discriminate More than Others? Evidence from 97 Field Experiments of Racial Discrimination in Hiring. Lincoln Quillian, Anthony Heath, Devah Pager, Arnfinn H. Midtbøen, Fenella Fleischmann, Ole Hexel. Sociological Science, June 17, 2019. DOI 10.15195/v6.a18

Abstract: Comparing levels of discrimination across countries can provide a window into large-scale social and political factors often described as the root of discrimination. Because of difficulties in measurement, however, little is established about variation in hiring discrimination across countries. We address this gap through a formal meta-analysis of 97 field experiments of discrimination incorporating more than 200,000 job applications in nine countries in Europe and North America. We find significant discrimination against nonwhite natives in all countries in our analysis; discrimination against white immigrants is present but low. However, discrimination rates vary strongly by country: In high-discrimination countries, white natives receive nearly twice the callbacks of nonwhites; in low-discrimination countries, white natives receive about 25 percent more. France has the highest discrimination rates, followed by Sweden. We find smaller differences among Great Britain, Canada, Belgium, the Netherlands, Norway, the United States, and Germany. These findings challenge several conventional macro-level theories of discrimination.

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Alex Tabarrok in Marginal Revolution https://marginalrevolution.com/marginalrevolution/2022/10/the-us-has-low-rates-of-hiring-discrimination.html, Oct 3, 2022:

There have now been lots of resume-audit studies in which identical resumes but for the "minority-distinct" name are sent out to employers and callback rates are measured. A meta-study of 97 field experiments (N = 200,000 job applicants) in 9 countries in Europe and North America finds there is some discrimination in every county but, if anything, the USA has one of the lower rates of discrimination while France and perhaps also Sweden have very high levels. These result's aren't  that surprising to those who travel but they run counter to the narrative that the US is uniquely or especially discriminatory because of its history of slavery and capitalism. Capitalism, in fact, is likely to predict less discrimination.

 

The authors make a number of interesting points:

...national histories of slavery and colonialism are neither necessary nor sufficient conditions for a country to have relatively high levels of labor market discrimination. Some countries with colonial pasts demonstrate high rates of hiring discrimination, but several countries without extensive colonial pasts (outside Europe), such as Sweden, demonstrate similar levels. Likewise, the lower rates of discrimination against minorities in the United States than we find for many European countries seem contrary to expectations that emphasize the primacy of connection to slavery in shaping the contemporary level of national discrimination. These results do not suggest that slavery and colonialism do not matter for levels of discrimination, rather they indicate that they matter in more complex ways than suggested by theories that posit simple, direct influences of the past on current discrimination.

And:

High discrimination in the French labor market seems inconsistent with claims made by some scholars that discourse or measurement of race and ethnicity itself will tend to produce more discrimination by promoting “groupism” and group stereotypes (Sniderman and Hagendoorn 2007). The efforts in France not to measure or formally discuss race or ethnicity do not seem to have led to less discrimination.

 

Rolf Degen summarizing... Genetic propensity for educational attainment was associated with an increased likelihood of using alcohol as an adolescent

Educational Attainment Polygenic Scores: Examining Evidence for Gene–Environment Interplay with Adolescent Alcohol, Tobacco and Cannabis Use. Christal N. Davis et al. Twin Research and Human Genetics, Oct 3 2022. https://doi.org/10.1017/thg.2022.33

Abstract: Genes associated with educational attainment may be related to or interact with adolescent alcohol, tobacco and cannabis use. Potential gene–environment interplay between educational attainment polygenic scores (EA-PGS) and adolescent alcohol, tobacco, and cannabis use was evaluated with a series of regression models fitted to data from a sample of 1871 adult Australian twins. All models controlled for age, age2, cohort, sex and genetic ancestry as fixed effects, and a genetic relatedness matrix was included as a random effect. Although there was no evidence that adolescent alcohol, tobacco or cannabis use interacted with EA-PGS to influence educational attainment, there was a significant, positive gene–environment correlation with adolescent alcohol use at all PGS thresholds (ps <.02). Higher EA-PGS were associated with an increased likelihood of using alcohol as an adolescent (ΔR2 ranged from 0.5% to 1.1%). The positive gene–environment correlation suggests a complex relationship between educational attainment and alcohol use that is due to common genetic factors.

No evidence of any political learning on social media in observational studies, and statistically significant but substantively small increases in knowledge in experiments, across social media platforms, types of knowledge, countries, & periods

Do people learn about politics on social media? A meta-analysis of 76 studies. Eran Amsalem, Alon Zoizner. Journal of Communication, jqac034, September 29 2022. https://doi.org/10.1093/joc/jqac034

Abstract: Citizens turn increasingly to social media to get their political information. However, it is currently unclear whether using these platforms actually makes them more politically knowledgeable. While some researchers claim that social media play a critical role in the learning of political information within the modern media environment, others posit that the great potential for learning about politics on social media is rarely fulfilled. The current study tests which of these conflicting theoretical claims is supported by the existing empirical literature. A preregistered meta-analysis of 76 studies (N = 442,136) reveals no evidence of any political learning on social media in observational studies, and statistically significant but substantively small increases in knowledge in experiments. These small-to-nonexistent knowledge gains are observed across social media platforms, types of knowledge, countries, and periods. Our findings suggest that the contribution of social media toward a more politically informed citizenry is minimal.

What Makes Single Life Attractive: More time for oneself, focusing on own goals and having no one dictating actions; plus men found the freedom to flirt around more important than women

What Makes Single Life Attractive: an Explorative Examination of the Advantages of Singlehood. Menelaos Apostolou & Chistoforos Christoforou. Evolutionary Psychological Science, Oct 1 2022. https://link.springer.com/article/10.1007/s40806-022-00340-1

Abstract: Many people do not have an intimate partner, one reason being that they prefer to be single. The current research aimed to address the question what makes single life appealing, that is, to identify the possible advantages of being single. More specifically, Study 1 employed open-ended questionnaires on a sample of 269 Greek-speaking participants, and identified 84 such advantages. By using quantitative research methods on a sample of 612 Greek-speaking participants, Study 2 classified these advantages into 10 broader categories. The “More time for myself,” followed by the “Focus on my goals,” and the “No one dictates my actions,” were rated as the most important. Men found the “Freedom to flirt around” more important than women, while women found the Focus on my goals and the “No tensions and fights” more important than men. In addition, younger participants rated the Focus on my goals as more important than older ones. Furthermore, low scorers in mating performance found the identified advantages more important than high scorers.

Is regulatory quality declining?

The Next Phase of Regulatory Reform. James Broughel. National Affairs, Summer 2022. https://www.nationalaffairs.com/publications/detail/the-next-phase-of-regulatory-reform

Excerpts... Read the full article, please:

One example of such evidence-free regulation in recent years comes from the Department of Health and Human Services (HHS). In 2021, HHS repealed a rule enacted by the Trump administration that would have required the agency to periodically review its regulations for their impact on small businesses. The measure was known as the SUNSET rule because it would attach sunset provisions, or expiration dates, to department rules. If the agency failed to conduct a review, the regulation expired.

Ironically, in proposing to rescind the SUNSET rule, HHS argued that it would be too time consuming and burdensome for the agency to review all of its regulations. Citing almost no academic work in support of its proposed repeal — a reflection of the anti-consequentialism that animates so much contemporary regulatory policy — the agency effectively asserted that assessing the real-world consequences of its existing rules was far less pressing an issue than addressing the perceived problems of the day (by, of course, issuing more regulations).

Through its actions, HHS has rejected the very notion of having to review its own rules and assess whether they work. In fact, the suggestion that agencies review their regulations is an almost inexplicably divisive issue in Washington today. "Retrospective review" has become a dirty term, while cost-benefit analysis has morphed into a tool to judge intentions rather than predict real-world consequences. The shift highlights how far the modern administrative state has drifted from the rational, evidence-based system envisioned by the law-and-economics movement just a few decades ago.

In today's administrative state, intellectual fads appear to be in the driver's seat, while science and economics are simply along for the ride. Despite pronouncements to the contrary, few intellectuals seem genuinely interested in "following the science": Too many have their careers, social status, and sense of personal identity wrapped up in perpetuating the status quo.

Smiling makes you look older, even when you wear a mask, due to eye wrinkling

Smiling makes you look older, even when you wear a mask: the effect of face masks on age perception. Tzvi Ganel & Melvyn A. Goodale. Cognitive Research: Principles and Implications volume 7, Article number: 84. Sep 6 2022. https://cognitiveresearchjournal.springeropen.com/articles/10.1186/s41235-022-00432-3

Abstract: The widespread use of face masks in the era of the Covid-19 pandemic has promoted research on their effect on the perception and recognition of faces. There is growing evidence that masks hinder the recognition of identity and expression, as well as the interpretation of speech from facial cues. It is less clear whether and in what manner masks affect the perception of age from facial cues. Recent research has emphasized the role of the upper region of the face, a part not covered by a mask, in the evaluation of age. For example, smile-related wrinkles in the region of the eyes make smiling faces appear older than neutral faces of the same individuals (the aging effect of smiling, AES). In two experiments, we tested the effect of face masks on age evaluations of neutral and smiling faces in a range of different age groups from 20 to 80 years. The results showed that smiling faces were perceived as older than neutral faces even when individuals were wearing a face mask—and there was no effect of masks on bias in age evaluations. Additional analyses showed reduced accuracy in age evaluations for smiling compared to neutral faces and for masked compared to unmasked faces. The results converge on previous studies emphasizing the importance of the upper region of the face in evaluations of age.

Significance statement: In this manuscript, we provide a comprehensive investigation of the effect of masks on different aspects of age evaluations. Within this context, we looked at the effect of masks on age evaluations of neutral and smiling faces. We found that wearing a face mask does not diminish the well-established effect of smiling on age perception: the fact that when people smile, they look older. In addition, we showed that contrary to previous suggestions, masks do not make people appear to be younger or older. The only difference in age evaluations between masked and unmasked faces was a moderate decrease in accuracy for age evaluations of masked faces. The findings confirm that the perception of age is driven largely by the upper part of the face and that the wrinkling of the eyes that occurs when people smile is responsible for the bias in age perception. These results provide timely insights on the effect of masks on face perception and on the processes that underlie the perception of facial age.

The ubiquity of resilience is one of the most consistent findings in the trauma literature

Myths of Trauma: Why Adversity Does Not Necessarily Make Us Sick. Joel Paris. Oxford Univ. Press, 2022. https://global.oup.com/academic/product/myths-of-trauma-9780197615768

- Focuses on the question of why some people fall ill while others show resilience in the face of adversity.

- Warns clinicians about the tendency to overdiagnose PTSD and overemphasize traumatic events in patients' life histories.

- Addresses the trend toward a "trauma focus" in therapy and offers an alternative, taking personality and life course into account.

The claim that a small number of repeat offenders are responsible for the majority of sexual assaults on college campuses reflects belief in a just & good status quo, and a preference for simple stories

What is the psychological appeal of the serial rapist model? Worldviews predicting endorsement. Ana P. Gantman, Elizabeth Levy Paluck. Behavioural Public Policy, September 30 2022. https://www.cambridge.org/core/journals/behavioural-public-policy/article/what-is-the-psychological-appeal-of-the-serial-rapist-model-worldviews-predicting-endorsement/732E0DC20E4742A09FEB013E5D466C96

Abstract: The serial rapist model claims that a small number of intentional, repeat offenders are responsible for the majority of sexual assaults on college campuses. The model has formed the dominant argument for some of the most popular forms of campus intervention programs and is cited by high profile advocates and policymakers. Despite enthusiasm for the serial rapist model, it is not empirically well-supported and is contradicted by recent robust data. In this article, we ask: why does the serial rapist model have such broad and enduring appeal? In two US-based samples, one convenience and one representative, we find that people's endorsement of the serial rapist model correlates with worldviews that cohere around ideas of a just and good status quo, and a preference for simple stories. Specifically, we find a positive relationship between endorsement of the serial rapist model and belief in a just world, system justification, social dominance orientation, need for closure and essentialism.

Ancient DNA suggests that artificial islands were party spots for the elite

New integrated molecular approaches for investigating lake settlements in north-western Europe. Antony G. Brown et al. Antiquity, Sep 28 2022. https://www.cambridge.org/core/journals/antiquity/article/new-integrated-molecular-approaches-for-investigating-lake-settlements-in-northwestern-europe/7A0304934781CF67D37DF76FCC87C54B

Abstract: Lake settlements, particularly crannogs, pose several contradictions—visible yet inaccessible, widespread yet geographically restricted, persistent yet vulnerable. To further our understanding, we have developed the integrated use of palaeolimnological (scanning XRF, pollen, spores, diatoms, chironomids, Cladocera, microcharcoal, biogenic silica, SEM-EDS, stable-isotopes) and biomolecular (faecal stanols, bile acids, sedaDNA) analyses of proximal and through-crannog cores in south-west Scotland and Ireland. Both can be effective methods sets for revealing occupation chronologies and identifying on-crannog activities and practices. Strong results from sedaDNA and lipid biomarker analyses demonstrate probable on-site animal slaughter, food storage and possible feasting, suggesting multi-period, elite site associations, and the storage and protection of valuable resources.

Context and discussion

The scientific techniques outlined here can provide sophisticated insights into the lifeways of societies ranging from the Neolithic to the post-medieval periods (AD 1603–present), even if via the cultural filter of wetland site activities. A key task for future work is to integrate these environmental methods with the more representative evidence generated by excavation of crannog settlements and associated dryland sites, and their wider cultural contexts. Focusing more specifically on crannogs, the frequent identification of ‘high-status’ activities and goods on some of these sites not only supports their role as places for the protective custody of valuable resources, but also suggests a degree of social exclusion combined with the display of power and wealth (O'Sullivan Reference O'Sullivan2004). Although seemingly low-status crannogs have been recorded, such as Sroove in Ireland (Boyle Reference Boyle2004), this impression may be the result of later reuse and disturbance, as the scale of resources required for crannog construction implies considerable investment. Indeed, biomolecular (and geochemical) methods may also be able to identify earlier activities that have left no trace in the on-site material culture, particularly as this could include infrequent events, such as feasting or ceremonial activities.

Shelley (Reference Shelley2009) has shown that for the medieval period in Scotland, crannogs can be regarded as watery lodges or palaces, which later went out of fashion as display became increasingly mediated through estates, mansions and gardens. The royal association of many crannogs suggests that this status display may also have been a factor during earlier periods in both Scotland and Ireland. Similarly, there was ecclesiastical use of some crannogs—especially in the early medieval period (AD 410–1066), following the model of ascetic monasticism whereby a central monastery was surrounded by satellite hermitages in remote locations and, particularly, on islands—although this was far more variable in Ireland (Bitel Reference Bitel, Alison and Bitel2020). An additional element here is the early Christian tradition of islands as places of holiness, retreat and redemption—a practise which can also have practical advantages through a degree of protection and self-sufficiency. Religious associations are visible through artefacts, such as crosses, and the later documented use of crannogs by the Church (Shelley Reference Shelley2009; Stratigos & Noble Reference Stratigos and Nobel2015). All of these considerations imply that the use and importance of crannogs were highly variable in different periods and places. One implication is that there is a fundamental limit to what we can discover about crannogs by studying them in isolation. A key insight comes from their changing use over time, but this relies entirely on increasing the number of dated crannogs, dating their construction and reuse, and comparing these dates to nearby dryland sites (e.g. settlements, raths and ringforts).

Non-conformity in mate choice: Immigrant females who do not conform to the local trend have sons, grandsons, etc. of the non-preferred phenotype, which negatively and cumulatively affects fitness over generations

Conformity in mate choice, the overlooked social component of animal and human culture. Sabine Nöbel et al. Biological Reviews, September 29 2022. https://doi.org/10.1111/brv.12899

Abstract: Although conformity as a major driver for human cultural evolution is a well-accepted and intensely studied phenomenon, its importance for non-human animal culture has been largely overlooked until recently. This limited for decades the possibility of studying the roots of human culture. Here, we provide a historical review of the study of conformity in both humans and non-human animals. We identify gaps in knowledge and propose an evolutionary route towards the sophisticated cultural processes that characterize humanity. A landmark in the study of conformity is Solomon Asch's famous experiment on humans in 1955. By contrast, interest in conformity among evolutionary biologists has only become salient since the turn of the new millennium. A striking result of our review is that, although studies of conformity have examined many biological contexts, only one looked at mate choice. This is surprising because mate choice is probably the only context in which conformity has self-reinforcing advantages across generations. Within a metapopulation, i.e. a group of subpopulations connected by dispersing individuals, dispersers able to conform to the local preference for a given type of mate have a strong and multigenerational fitness advantage. This is because once females within one subpopulation locally show a bias for one type of males, immigrant females who do not conform to the local trend have sons, grandsons, etc. of the non-preferred phenotype, which negatively and cumulatively affects fitness over generations in a process reminiscent of the Fisher runaway process. This led us to suggest a sex-driven origin of conformity, indicating a possible evolutionary route towards animal and human culture that is rooted in the basic, and thus ancient, social constraints acting on mating preferences within a metapopulation. In a generic model, we show that dispersal among subpopulations within a metapopulation can effectively maintain independent Fisher runaway processes within subpopulations, while favouring the evolution of social learning and conformity at the metapopulation scale; both being essential for the evolution of long-lasting local traditions. The proposed evolutionary route to social learning and conformity casts surprising light on one of the major processes that much later participated in making us human. We further highlight several research avenues to define the spectrum of conformity better, and to account for its complexity. Future studies of conformity should incorporate experimental manipulation of group majority. We also encourage the study of potential links between conformity and mate copying, animal aggregations, and collective actions. Moreover, validation of the sex-driven origin of conformity will rest on the capacity of human and evolutionary sciences to investigate jointly the origin of social learning and conformity. This constitutes a stimulating common agenda and militates for a rapprochement between these two currently largely independent research areas.

VII. CONCLUSIONS

(1) The strength of our proposed pathway rooted in mate choice and runaway sexual selection is that it explains the evolution of social learning and conformity, as well as culture.

(2) One of the major challenges therefore for empirical studies of social learning is to find out whether the detection of majority behaviour in mate copying preceded (in evolutionary time) the detection of majority behaviour in other contexts such as foraging and to what extent it evolved analogously or homologously. For that goal we will need to determine in a large range of species the shape of the response function of conformity in mate choice, and other contexts with experiments manipulating the level of majority. Altogether, this provides a rich agenda for future research.

(3) In the expectation of such information, the tentative model we propose and simulate here for the evolution of conformity, and all its cultural evolution consequences, casts surprising light on one of the major processes that has participated in making us humans. Sex might play a bigger role than previously thought in the long-run development of cultural traditions.

Placebo Analgesia not only reduces empathy, also Reduces Costly Prosocial Helping to Lower Another Person’s Pain

Placebo Analgesia Reduces Costly Prosocial Helping to Lower Another Person’s Pain. Helena Hartmann et al. Psychological Science, Sep 29 2022. https://doi.org/10.1177/09567976221119727

Abstract: Painkiller administration lowers pain empathy, but whether this also reduces prosocial behavior is unknown. In this preregistered study, we investigated whether inducing analgesia through a placebo painkiller reduced effortful helping. When given the opportunity to reduce the pain of another person, individuals experiencing placebo analgesia (n = 45 adults from Austria; 21 male, 24 female) made fewer prosocial choices at the lowest helping level and exerted less physical effort when helping, compared with controls whose pain sensitivity was unaltered (n = 45; 21 male, 24 female). Self-reported empathic unpleasantness positively correlated with prosocial choices across the whole sample. While not replicating group differences in empathy, a mediation analysis revealed that the level of unpleasantness to other people’s pain fully mediated the effect of placebo analgesia on prosocial choices. Given the importance of prosociality for social cohesion, these findings have broad potential implications both for individuals under the influence of painkillers and for society at large.

Both men and women perceived women with nipple erection as less intelligent, less moral, more likely to engage in sexual behaviors, & as having poorer sexual health & less sexually manipulative

 Burch, R. L., & Widman, D. R. (2022). The point of nipple erection 3: Sexual and social expectations of women with nipple erection. Evolutionary Behavioral Sciences, Sep 2022. https://doi.org/10.1037/ebs0000312

Abstract: If nipple erection signals/is a cue to sexual interest or arousal, we would expect that women with nipple erection would be sexualized: having a presumed higher sexual arousal and promiscuity and lower mental abilities and morality. To examine this, 234 participants rated pictures of women with and without salient nipple erection (faces were obscured to eliminate facial cues). Participants completed a hypothetical sexual behavior profile (30 items including perceptions of morality and intelligence) for each stimulus photo. Both men and women perceived women with nipple erection as less intelligent, less moral, and more likely to engage in sexual behaviors. These are the primary markers of sexual objectification. They also rated these women as having poorer sexual health and being less sexually manipulative. Men perceived all the women in the stimulus photos as being less moral and having more male sexual partners, indicating that men objectified the stimuli overall more than women. Women reported that women with erect nipples had more male sex partners, lost their virginity at a younger age, and had lower quality relationships. In summary, female nipple erection, which is an uncontrollable reflex, triggers sexualization and objectification by both men and women who observe it.

Impact Statement: Nipple erection is a cue that triggers sexualization and objectification of women; women with nipple erection are thought of as less intelligent, less moral, and more promiscuous by both men and women. Women cannot control their nipple erection, yet these data show that it is used by men and women to make presumptions about women’s character and behavior.

Schizophrenia has been an evolutionary paradox: it has high heritability, but it is associated with decreased reproductive success

Schizophrenia: the new etiological synthesis. Markus J. Rantala et al. Neuroscience & Biobehavioral Reviews, September 28 2022, 104894. https://doi.org/10.1016/j.neubiorev.2022.104894

Highlights
•    Schizophrenia (SZR) is rare or nonexistent in hunter-gatherer populations
•    Several microbial infections can trigger SZR
•    SZR is associated with neuroinflammation and gut dysbiosis
•    Parasite x genotype x stress interaction forms the new etiological synthesis for SZR
•    Evolutionary mismatch explains SZR better than other evolutionary hypotheses

Abstract: Schizophrenia has been an evolutionary paradox: it has high heritability, but it is associated with decreased reproductive success. The causal genetic variants underlying schizophrenia are thought to be under weak negative selection. To unravel this paradox, many evolutionary explanations have been suggested for schizophrenia. We critically discuss the constellation of evolutionary hypotheses for schizophrenia, highlighting the lack of empirical support for most existing evolutionary hypotheses—with the exception of the relatively well supported evolutionary mismatch hypothesis. It posits that evolutionarily novel features of contemporary environments, such as chronic stress, low-grade systemic inflammation, and gut dysbiosis, increase susceptibility to schizophrenia. Environmental factors such as microbial infections (e.g., Toxoplasma gondii) can better predict the onset of schizophrenia than polygenic risk scores. However, researchers have not been able to explain why only a small minority of infected people develop schizophrenia. The new etiological synthesis of schizophrenia indicates that an interaction between host genotype, microbe infection, and chronic stress causes schizophrenia, with neuroinflammation and gut dysbiosis mediating this etiological pathway. Instead of just alleviating symptoms with drugs, the parasite x genotype x stress model emphasizes that schizophrenia treatment should focus on detecting and treating possible underlying microbial infection(s), neuroinflammation, gut dysbiosis, and chronic stress.

6. Critical evaluation of previous evolutionary hypotheses for schizophrenia

Many of these previous evolutionary hypotheses lack proper empirical validation (Fig. 2) and, above and beyond the critical discussion presented in this article, scientific approaches to schizophrenia would benefit from critical appraisals and rigorous research devising crucial experiments that pitch each hypothesis against one other (cf. Platt, 1964). Even though some of the previous evolutionary hypotheses presented above might explain some of the characteristic manifestations of psychosis or delusions and their relations to the genetics of schizophrenia, all of them—with the exception of the mismatch hypothesis—fail to provide a convincing explanation for the negative symptoms of schizophrenia such as blunting of affect, violent behavior, aggression, apathy, anhedonia, loss of motivation, or cognitive deficit. The hypotheses—with the exception of the mismatch hypothesis—also fail to explain impairments in executive functions typically observed in schizophrenic patients. In addition, the hypotheses have not been able to explain why schizophrenia is commonly comorbid with many other mental disorders (Buckley et al., 2009, Tsai and Rosenheck, 2013). Major depressive disorder, for instance, is a common psychiatric comorbidity in patients with schizophrenia. A recent meta-analysis found that 32.6% of patients with schizophrenia would meet the diagnostic criteria of major depressive disorder (Etchecopar-Etchart et al., 2021) and symptoms of major depressive disorder are common prodromal symptoms of psychosis (Hafner and an der Heiden, 2011). In addition, a 12-month follow-up study found that 80% of patients with first-episode psychosis would also fulfill the diagnostic criteria of major depressive disorder (Upthegrove et al., 2010). Psychosis may also occur in patients with major depressive disorder, bipolar disorder, and schizoaffective disorder (Dubovsky et al., 2021), highlighting that these disorders are not completely separate entities. The comorbidity of these disorders is most elegantly explained by the parasite hypothesis of schizophrenia presented in Section 2, as well as their shared genetic basis (Anttila et al., 2018; Hindley, 2021; Legge et al., 2021). These disorders are characterized by sickness behavior that is caused either by the activation of the immune system via low-grade systemic inflammation (Rantala et al., 2018, Rantala et al., 2021) or direct manipulation of host behavior by parasites (Borráz-León et al., 2021).

Schizophrenia is not a discrete disorder and separating it from other disorders is often difficult. This makes all previous evolutionary hypotheses (except the mismatch hypothesis) somewhat problematic. The classification of these disorders is often difficult because of overlapping symptoms, which may result in a patient receiving different diagnoses from different psychiatrists. Hallucinations and delusions occur also in patients with bipolar disorder and Alzheimer’s disease. About half of Alzheimer’s patients have psychosis (Murray et al., 2014) and a study on 1 342 patients with bipolar disorder type I found that 73.8% had a lifetime prevalence of psychotic symptoms (van Bergen et al., 2019). A plausible scientific framework would also explain occurrences of psychosis, delusions, and hallucinations in other disorders, not just in schizophrenia. The parasite hypothesis is able to explain why psychosis may occur in other disorders: differences in the parasite species that individuals are infected with, differences in timing of infection, genetic vulnerability, and microbiota may explain whether a person will have symptoms of schizophrenia or, say, bipolar disorder, or depression with psychotic features (see Section 2.3).

Schizophrenia has traditionally been classified into different subtypes that differ in symptomatology. The prevalence of these subtypes varies geographically and by time (Jablensky et al., 1992). Schizophrenia is not a single disorder. Instead, it seems that schizophrenia is only an umbrella term for a group of separate disorders with some overlapping symptoms. None of the previous evolutionary explanations for schizophrenia have explained the heterogeneous subtypes of schizophrenia and their persistence in modern human populations—although the mismatch hypothesis and the balanced polymorphism hypothesis could conceivably account for these findings. The parasite hypothesis, in contrast, provides an explanation for the heterogeneity by suggesting that it results from different parasite/pathogen species causing schizophrenia and/or individual differences in responses to microbial infections (see Section 2).

With the exception of the mismatch hypothesis, all previous evolutionary hypotheses also fail to provide a rationale for why and how neuroinflammation plays a role in schizophrenia (see Section 2.1.) and why there are inflammatory marker subtypes in schizophrenia (see e.g., Lizano et al., 2021). The parasite hypothesis, in combination with the mismatch hypothesis, explains why neuroinflammation occurs in schizophrenia and why there are different inflammatory marker subtypes. The parasite x genotype x stress model also explains why schizophrenia is more common in cities than in rural areas (see Section 3). Since chronic stress—which is often a triggering factor in psychosis—is rare among people with hunter-gatherer lifestyle(s) (Brenner et al., 2015), the parasite x genotype x stress model, coupled with the mismatch hypothesis, explains why schizophrenia is rare among them (cf. (Abed and Abbas, 2011b). Except for the mismatch hypothesis, previous evolutionary hypotheses for schizophrenia have not been able to explain why schizophrenia is more common in people with modern western lifestyles and why exposure to natural environments in neighborhoods or around residential areas is associated with lower schizophrenia rates (Engemann et al., 2019, Engemann et al., 2020, Kristine et al., 2018).

None of the previous evolutionary hypotheses have been able to explain why adverse life events play an important role in the onset of schizophrenia and psychosis. For example, exposure to childhood trauma is associated with a 2- to 3-fold increase in risk of psychotic outcomes (Croft et al., 2019, Rokita et al., 2021, Trotta et al., 2015). Likewise, cumulative stress pathophysiology is often a triggering factor in psychosis (Nugent et al., 2015), and cortical stress regulation is disrupted in patients with schizophrenia (Schifani et al., 2018). There are also differences in gut microbiota between healthy people and those with schizophrenia (Section 4). These observations do not fit well with previous evolutionary hypotheses for schizophrenia, with the exception of the mismatch hypothesis. Thus, most existing evolutionary hypotheses do not explain empirical findings about schizophrenia and have acquired limited empirical support of their own. The parasite x genotype x stress model, in contrast, suggests that stress negatively impacts immune function and thereby facilitates parasitic/pathogenic effects on the brain (see Section 2).

Many of the previous evolutionary explanations of schizophrenia are examples of evolutionary storytelling: they provide adaptive explanations for a phenomenon which is neither adaptive nor an adaptation, but rather a pathological side effect of microbial infection and chronic stress. Although the parasite x genotype x stress model can explain the occurrence of schizophrenia at one level of analysis, the sexual selection hypothesis (Nettle, 2001), the reformulated social brain hypothesis (Abed and Abbas, 2011b), and the life history hypothesis of schizophrenia (Del Giudice, 2010, 2017; Del Giudice et al., 2014) may partly explain why genetic variants that interact with pathogen infection and chronic stress (Fig. 1) may exist in the human gene pool in the first place. Furthermore, the mismatch hypothesis is an integral component of the parasite x genotype x stress model; environmental mismatch, after all, leads to the chronic stress that makes individuals with contemporary western lifestyles more susceptible to schizophrenia than those with traditional lifestyles (Fig. 1). Despite the abundant evidence supporting the parasite x genotype x stress model coupled with the environmental mismatch hypothesis of schizophrenia, it is also possible that future research will discover other hypotheses at proximate and ultimate levels of analysis that more accurately carve the biopsychosocial nature of schizophrenia at its joints.