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,

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.

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.

• 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,

• 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

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


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