Monday, January 7, 2999

Support Rolf Degen's work!

Please check Rolf Degen's twitter page and help him maintain his great service, excerpting papers about evolutionary psychology and related areas: https://twitter.com/DegenRolf

Check for yourself his summaries' quality. Please help him preserve his work!

Wednesday, February 20, 2019

Males show higher variability in morphological traits (height), social-emotional traits (emotional intelligence), cognitive traits (short-term memory ability), & markers of physical & financial health

Bateman’s Principle Hypothesis. Geher, G. et al. EvoS Journal, Jan 2019, http://evostudies.org/wp-content/uploads/2019/01/Geher-et-al_Vol8Iss1.pdf

ABSTRACT: In 1948, Bateman published a landmark paper bearing on the evolutionary variable of reproductive success (RS). Drawing on data regarding the life cycle of fruit flies, Bateman discovered that mating rates in various experiments all demonstrated higher variability in males than in females. Females were more likely to mate a moderate number of times while data from males were characterized by a clear variability in RS (with males likely to encounter low, moderate, high, or even extremely high levels of RS). This phenomenon, now known as Bateman’s Principle, has shown to be generally operative across various species including our own (Brown, Laland, & Mulder, 2013; Brown, Laland, & Mulder, 2009). The current work aims to address whether this basic asymmetry in variability across the sexes generalizes to trait domains that bear on RS. In other words, do males, relative to females, show higher variability in measures of morphological traits (e.g., height), social-emotional traits (e.g., emotional intelligence), cognitive traits (e.g., short-term memory ability), and important life outcome variables (e.g., markers of physical and financial health)? To address this issue, our methods included an intensive examination of the literature on male/female differences across a broad array of human domains. The literature review presented here addresses this idea, often referred to as the variability hypothesis (see Feingold, 1992), across a  broad-reaching suite of physical and behavioral dimensions. Ultimately, our results and conclusions provide strong evidence for the variability hypothesis in humans.

KEYWORDS: Sex Differences, Gender Differences, Variability, Evolutionary Psychology, Bateman’s Principle

Impact of yoga-based mind-body intervention: Re-established immunological tolerance by aiding remission at molecular and cellular level along with significant reduction in depression

Impact of yoga based mind-body intervention on systemic inflammatory markers and co-morbid depression in active Rheumatoid arthritis patients: A randomized controlled trial. Gautam, Surabhia | Tolahunase, Madhuria | Kumar, Umab | Dada, Rimaa. Restorative Neurology and Neuroscience, vol. Pre-press, no. Pre-press, pp. 1-19, 2018. https://content.iospress.com/articles/restorative-neurology-and-neuroscience/rnn180875

Abstract: Background:Recovery of the patients with rheumatoid arthritis (RA) depends on several physical and psychological factors, besides pharmacological treatment. Co-morbid depression adversely affects the outcome in RA. Usual medical therapies have a limited scope and fail to cure the psychological component of the disease. With advanced therapeutic options, achieving a state of remission has become the treatment goal, yoga based mind body intervention (MBI) may provide a holistic approach to its treatment dimension. Hence, MBIs become the need of hour as majority of diseases have a psychosomatic component. Objective:To explore the effect of Yoga based MBI on disease specific inflammatory markers and depression severity in active RA patients on routine disease modifying anti-rheumatic drugs (DMARDs) therapy.

Methods:A total of 72 RA patients were randomized into 2 groups: yoga group (yoga with DMARDs) and control group (DMARDs only). Blood samples were collected pre and post intervention for primary outcome measurements of systemic biomarkers. Disease activity score 28 erythrocyte sedimentation rate (DAS28ESR) and health assessment questionnaire disability index (HAQ-DI) were used to assess disease activity and functional status respectively at pre and post intervention time-points. Secondary outcome, depression severity, was assessed by Beck Depression Inventory II scale (BDI-II) at 2 weekly intervals during 8 weeks of the study interventional plan.

Results:After 8 weeks of yoga based MBI, there was significant decrease in the severity of RA as seen by reduction in levels of various systemic inflammatory markers as well as in DAS28ESR (p-value <0.0001; effect size = 0.210) and HAQ-DI (p-value 0.001; effect size = 0.159). Also, yoga group experienced a statistically significant time dependent step-wise decline in depression symptoms over the period of 8 weeks as compared to control group (p-value <0.0001; effect size = 0.5). Regression analysis showed greater reduction in the scores of BDI-II with DAS28ESR (R2 = 0.426; p <  0.0001) and HAQ-DI (R2 = 0.236; p = 0.003) in yoga group.

Conclusions: Yoga, a mind body intervention re-established immunological tolerance by aiding remission at molecular and cellular level along with significant reduction in depression. Thus in this inflammatory arthritis with a major psychosomatic component, yoga can be used as a complementary/adjunct therapy.

Keywords: Rheumatoid arthritis, yoga, immunomodulation, depression, inflammation, ageing, remission, oxidative stress

A meta-analysis of twin studies on genetic & environmental influences on spatial reasoning: Spatial ability is highly heritable, genetic contribution of spatial ability varies by age group, do not vary by sex

Genetic and environmental influences on spatial reasoning: A meta-analysis of twin studies. Michael J. King et al. Intelligence, Volume 73, March–April 2019, Pages 65-77. https://doi.org/10.1016/j.intell.2019.01.001

Highlights
• Spatial ability is highly heritable (meta-analytic mean a2 = .61).
• Genetic contribution of spatial ability varies by age group.
• Contributions do not vary by sex.
• Contributions do not vary by type of spatial ability measure.

Abstract: Behavioral genetic approaches, such as comparing monozygotic and dizygotic twins, are often used to evaluate the extent to which variations in human abilities are the result of genetic (heritable), shared environmental, and non-shared environmental factors. We conducted a meta-analysis on the twin study literature—comparing monozygotic and dizygotic twins—to provide clarity and a general consensus regarding the extent to which genetic and environmental factors contribute to variation in spatial ability. Consistent with previous work, we found that spatial ability is largely heritable (meta-analytic  = .61; 95% CI [.55, .66]), with non-shared environmental factors having a substantial impact (meta-analytic . = .43; 95% CI [.38, .49]), and shared environmental factors having very little impact (meta-analytic . = .07; 95% CI [.05, .10]). Moderator analyses were performed to establish if spatial ability type, sex, or age impacted the explanatory power of genetics or environmental factors. These effects did not differ significantly by sex or spatial ability type. However, the influence of shared environments did significantly differ depending on age. This result was driven by the youngest age group (ages 4–15) demonstrating relatively high amounts of shared environmental influence (c = .15, 95% CI [.10, .20]) compared with the other age groups (cs = .00–.07).

Keywords: Spatial reasoningBehavioral geneticsMeta-analysisCognitive developmentIntelligence

What Does it Mean to Have “No Personality” or “A Lot of Personality”? Those with a lot of personality were more liked, higher in extraversion, agreeableness, & openness, & less likely to be incidental characters

What Does it Mean to Have “No Personality” or “A Lot of Personality”? Natural Language Descriptions and Big Five Correlates. Jennifer V.Fayard, John Z. Clay, Felicia R. Valdez, Lesley A. Howard. Journal of Research in Personality, https://doi.org/10.1016/j.jrp.2019.02.004

Highlights
• A lot of personality had more complex qualitative description than no personality.
• A lot of personality was rated higher in extraversion than no personality.
• A lot of personality was rated higher in openness than no personality.
•  A lot of personality was liked more than no personality.

Abstract: The current study aimed to discover the meaning behind the common person descriptions “no personality” and “a lot of personality.” Participants provided narrative descriptions of both terms and rated the personalities of two fictional characters, one with “no personality” and one with “a lot of personality,” how much they liked each character, how central each character was in their story, and confidence in their ratings. Qualitative analysis found that four domains described “no personality” and eight described “a lot of personality.” Characters with a lot of personality were more liked, higher in extraversion, agreeableness, and openness, and less likely to be incidental characters. Finally, participants were less confident in their ratings for extraversion, openness, and agreeableness for “no personality.”

Keywords: Personality traitsperson perceptionqualitative

Irrespective of whether they were exposed to a disclaimer or not, most women who viewed ads featuring thin models thought that the image had been digitally modified

The effect of exposure to thin models and digital modification disclaimers on women's body satisfaction. Nehama Lewis  Ayellet Pelled  Nurit Tal‐Or. International Journal of Psychology, Feb 19 2019 https://doi.org/10.1002/ijop.12572

Abstract: This study tests the effectiveness of public health initiatives aimed at reducing the adverse effects of exposure to thin images in advertising on women's body satisfaction. Using an online experiment with 195 Israeli adult women, we test the effects of message factors that are expected to influence body satisfaction—the model's body size, and the presence and size of disclaimers. Compared with advertisements featuring a thin model, exposure to an average sized model was indirectly and positively associated with body size satisfaction, through the perception of the model's body size. However, exposure to disclaimers regarding digital modification of the model did not influence body satisfaction. Moreover, irrespective of whether they were exposed to a disclaimer or not, most participants who viewed ads featuring thin models thought that the image had been digitally modified. The results call for further research on the effectiveness of disclaimer labels for promoting body satisfaction.

Examined potential mechanism behind reduced birth rates related to unusually hot temperatures; found no significant effect on sexual activity on subsequent days

Ambient temperature and sexual activity: Evidence from time use surveys, Tamás Hajdu, Gábor Hajdu. Demographic Research, Volume 40 - Article 12 | Pages 307–318, DOI: 10.4054/DemRes.2019.40.12

Abstract

Background: Previous research has found that unusually hot temperatures reduce birth rates eight to ten months later.

Objective: We examine one of the potential mechanisms behind this relationship: the connection between ambient temperature and sexual activity.

Methods: We use individual-level data provided by three waves of the Hungarian Time Use Survey between 1986 and 2010 and daily weather data from the European Climate Assessment & Dataset project.

Results: Hot temperatures do not have a significant effect on sexual activity on a given day. Studying the dynamics of the relationship, we found that temperature does not influence sexual activity on subsequent days either.

Conclusions: Since high temperatures seem to have no negative effect on sexual activity, the relationship between temperature and sexual activity might be a mechanism of minor importance in the relationship between temperature and birth rates.

Contribution: Our paper is the first study of the relationship between ambient temperature and sexual activity that uses time use data.

Keywords: sexual behavior, temperature, time use, weather variability

Tuesday, February 19, 2019

In the late XIX century Britain had almost no mandatory shareholder protections, but had very developed financial markets; private contracting made the absence of statutory protections immaterial

Private Contracting, Law and Finance. Graeme G Acheson  Gareth Campbell  John D Turner. The Review of Financial Studies, hhz020, https://doi.org/10.1093/rfs/hhz020

Abstract: In the late nineteenth century Britain had almost no mandatory shareholder protections, but had very developed financial markets. We argue that private contracting between shareholders and corporations meant that the absence of statutory protections was immaterial. Using approximately 500 articles of association from before 1900, we code the protections offered to shareholders in these private contracts. We find that firms voluntarily offered shareholders many of the protections that were subsequently included in statutory corporate law. We also find that companies offering better protection to shareholders had less concentrated ownership.

JEL K22 - Business and Securities Law G34 - Mergers; Acquisitions; Restructuring; Corporate Governance N43 - Europe: Pre-1913 N23 - Europe: Pre-1913 G32 - Financing Policy; Financial Risk and Risk Management; Capital and Ownership Structure; Value of Firms; Goodwill G38 - Government Policy and Regulation

Can Money Buy Happiness? Evidence for European Countries: Happiness increases with individual income until a threshold of 27,913 Euro per year (rounded to 35,000 USD)

Can Money Buy Happiness? Evidence for European Countries. Gabriela Mihaela Muresan, Cristina Ciumas, Monica Violeta Achim. Applied Research in Quality of Life, https://link.springer.com/article/10.1007/s11482-019-09714-3

Abstract: This research comes to empirical investigate the influence of income on the level of happiness. Can money buy happiness? It’s one of the most frequently disputed and researched questions of all time. At first sight, it seems easy to assign a simple answer: yes or no, but the correct answer is more difficult than these. We start from the assumption that people need to be happy but also need financial resources to feel safe. We used a panel analysis on a sample of 26 European countries over the period 2008–2016. We found that happiness increases with individual income until a threshold of 27,913 Euro per year (rounded to 35,000 USD) in European countries. Also, we found that culture plays an essential role in the perception of happiness. Moreover, our results indicate that a lower power distance, a high individualism, a low level of uncertainty avoidance and a high indulgence statistically increase the level of happiness.

Truth-default theory: When people cognitively process the content of others’ communication, they typically do so in a manner characterized by unquestioned, passive acceptance

Documenting the Truth Default: The Low Frequency of Spontaneous, Unprompted Veracity Assessments in Deception Detection. David D Clare  Timothy R Levine. Human Communication Research, hqz001, https://doi.org/10.1093/hcr/hqz001

Abstract: The core idea of truth-default theory (T. R. Levine, 2014) is that when people cognitively process the content of others’ communication, they typically do so in a manner characterized by unquestioned, passive acceptance. Two deception detection experiments tested the existence of the truth-default by comparing prompted and unprompted evaluations of others. The first experiment involved viewing videotaped communication, and the second experiment involved live, face-to-face interactions. In both experiments, research confederates told the truth and lied about plausible and implausible autobiographical content. Participants completed both traditional, prompted, dichotomous truth-lie assessments and open-ended thought-listing measures. The order of the two types of measures was experimentally varied. The results supported the concept of a truth-default. Coded thought listings showed that, absent prior prompting, receivers mentioned consideration of the veracity of other’s communication less than 10% of the time.



The use of pornography and the relationship between pornography exposure and sexual offending in males: A systematic review

The use of pornography and the relationship between pornography exposure and sexual offending in males: A systematic review. Emily Mellor, Simon Duff. Aggression and Violent Behavior, https://doi.org/10.1016/j.avb.2019.02.003

Highlights
• There is no clear evidence to suggest a relationship between pornography and offending.
• Men who offend report less exposure to pornography
• Pornography use does not result in more harm to the victim.
• Definitions of pornography are poor.

Abstract
Background: Exposure to pornography is common, although research examining the use of pornography, and the relationship between exposure to pornography and offending, is contradictory. The purpose of this systematic review was to determine whether there was an association between pornography exposure and sexual offending in males.

Method: A comprehensive search of eight electronic databases was undertaken to systematically identify literature relating to pornography and offending. Reference lists of key journals were hand searched and contact was made with experts in the field to identify any unpublished work. A total of twenty-one studies were included in the review and all were assessed using a quality criteria tool adapted from the Critical Appraisal Skills Programme (CASP, 2018).

Results: From the twenty-one studies included in the review, studies explored pornography use either prior to or during offending. Studies exploring the effects of pornography assessed recidivism, seriousness of the sexual offence and deviant sexual fantasies. The data synthesis indicated that the impact of pornography on offending is not always negative but that it is complex, particularly due to issues related to defining pornography.

Conclusion: The review yielded mixed findings largely due to variations in samples and a lack of agreed definitions for pornography. Recommendations are provided regarding the need for more recent longitudinal studies able to capture any possible changes within the pornography literature and its effect on sexual offenders, and the need for studies that provide specific definitions for pornography.

Consensus seeking –abandoning one’s own judgment to align with a group majority– is a fundamental feature of human social interaction; often occurs in the absence of any apparent economic/social gain

The Expression and Transfer of Valence Associated with Social Conformity. Prachi Mistry & Mimi Liljeholm. Scientific Reports, volume 9, Article number: 2154 (Feb 15 2019). https://www.nature.com/articles/s41598-019-38560-4

Abstract: Consensus seeking – abandoning one’s own judgment to align with a group majority – is a fundamental feature of human social interaction. Notably, such striving for majority affiliation often occurs in the absence of any apparent economic or social gain, suggesting that achieving consensus might have intrinsic value. Here, using a simple gambling task, in which the decisions of ostensible previous gamblers were indicated below available options on each trial, we examined the affective properties of agreeing with a group majority by assessing the trade-off between social and non-social currencies, and the transfer of social valence to concomitant stimuli. In spite of demonstrating near-perfect knowledge of objective reward probabilities, participant’s choices and evaluative judgments reflected a reliable preference for conformity, consistent with the hypothesized value of social alignment.



Effects of celebrity gossip on trust: Prosocial women trusted their interaction partners more after gossiping, whereas proself women trusted their partners less

The effects of celebrity gossip on trust are moderated by prosociality of the gossipers. Konrad Rudnicki, Charlotte J.S. De Backer, Carolyn Declerck. Personality and Individual Differences, Volume 143, 1 June 2019, Pages 42-46. https://doi.org/10.1016/j.paid.2019.02.010

Abstract: Previous research suggests that gossip serves several functions in regulating group dynamics (e.g. bonding, entertainment) and is preferentially used by prosocial individuals to protect the group from exploitation. However, it is still unclear what mechanisms underlie these functions and compel prosocial people to gossip. Because gossip provides information about the attitudes and moral views of an interaction partner we hypothesized that for prosocial individuals it functions as a cue that enables trust to be established, even among strangers. We conducted an experiment with 122 female participants who did not know each other prior to the study. They were asked to gossip about celebrities (the most likely form of gossip between strangers) or perform a creativity task for 20 min in pairs before playing a trust game. Participants were categorized as prosocial or proself based on their social value orientation (SVO). To additionally test if the effect of gossip on trust differs in real-life interactions and online, participants interacted either face-to-face or online. The results show that, irrespective of the environment, prosocial women trusted their interaction partners more after gossiping, whereas proself women trusted their partners less.

Self-esteem as an adaptive sociometer of mating success: Evaluating evidence of sex-specific psychological design across 10 world region

Self-esteem as an adaptive sociometer of mating success: Evaluating evidence of sex-specific psychological design across 10 world regions. David P. Schmitt, Peter K. Jonason. Personality and Individual Differences, Volume 143, 1 June 2019, Pages 13-20, https://doi.org/10.1016/j.paid.2019.02.011

Abstract: According to an evolutionary-adaptive version of sociometer theory, because men, more than women, have faced the adaptive problem of obtaining large numbers of willing short-term mating partners, positive associations between self-esteem and number of past sexual partners should be stronger among men than women. We correlated self-esteem with number of past sexual partners in a sample of more than 16,000 people across 10 major regions of the world. Results largely supported our prediction. This amply powered research investigation provided a limited, but revealing, test of an evolutionary-adaptive sociometer theory of self-esteem. For men, successfully accessing more sexual partners, regardless of personal desire or the mores of wider culture, was generally associated with higher self-esteem. For women, the links between numbers of sexual partners and self-esteem were much more dependent on culture.

Monday, February 18, 2019

Operationalization of Excessive Masturbation—Development of the Excessive Masturbation Scale (EMS)

Operationalization of Excessive Masturbation—Development of the EMS. Wiebke Driemeyer, Jan Snagowski, Christian Laier, Michael Schwarz & Matthias Brand. Sexual Addiction & Compulsivity, Volume 25, 2018 - Issue 2-3, Pages 197-215. https://doi.org/10.1080/10720162.2018.1495586 

Abstract: Research has recently focused on hypersexual behavior and Internet-pornography-viewing disorder as potential psychopathological conditions, but specific aspects of the phenomena have been widely neglected. This study aimed to investigate excessive masturbation as a subset and symptom of hypersexual behaviors. 2 studies with independent samples have been conducted. In study 1 (n = 146), the Excessive Masturbation Scale (EMS) was designed and tested via explorative factor analysis. In study 2 (n = 255), the psychometric properties of the EMS were evaluated by confirmatory factor analysis. A replicable 2-factor structure (“Coping” and “Loss of Control”) was identified. The EMS showed good psychometric properties and provides a promising basis for further research.