Greater Male Variability in Creativity Outside the WEIRD World

Social Class, Sex, and the Ability to Recognize Emotions: The Main Effect is in the Interaction

Previous research has demonstrated an inverse relation between subjective social class (SSC) and performance on emotion recognition tasks. Study 1 (N = 418) involved a preregistered replication of this effect using the Reading the Mind in the Eyes Task and the Cambridge Mindreading Face-Voice Battery. The inverse relation replicated; however, exploratory analyses revealed a significant interaction between sex and SSC in predicting emotion recognition, indicating that the effect was driven by males. In Study 2 (N = 745), we preregistered and tested the interaction on a separate archival dataset. The interaction replicated; the association between SSC and emotion recognition again occurred only in males. Exploratory analyses (Study 3; N = 381) examined the generalizability of the interaction to incidental face memory. Our results underscore the need to reevaluate previous research establishing the main effects of social class and sex on emotion recognition abilities, as these effects apparently moderate each other.

The sexual selection of creativity: A nomological approach

Cultural innovations, such as tools and other technical articles useful for survival, imply that creativity is an outcome of evolution. However, the existence of purely ornamental items obfuscates the functional value of creativity. What is the functional or adaptive value of aesthetic and intellectual ornaments? Recent evidence shows a connection between ornamental creativity, an individual's attractiveness, and their reproductive success. However, this association is not sufficient for establishing that creativity in humans evolved by sexual selection. In this critical review, we synthesize findings from many disciplines about the mechanisms, ontogeny, phylogeny, and the function of creativity in sexual selection. Existing research indicates that creativity has the characteristics expected of a trait evolved by sexual selection: genetic basis, sexual dimorphism, wider variety in males, influence of sex hormones, dysfunctional expressions, an advantage in mating in humans and other animals, and psychological modules adapted to mating contexts. Future studies should investigate mixed findings in the existing literature, such as creativity not being found particularly attractive in a non-WEIRD society. Moreover, we identified remaining knowledge gaps and recommend that further research should be undertaken in the following areas: sexual and reproductive correlates of creativity in non-WEIRD societies, relationship between androgens, development, and creative expression, as well as the impact of ornamental, technical and everyday creativity on attractiveness. Evolutionary research should analyze whether being an evolved signal of genetic quality is the only way in which creativity becomes sexually selected and therefore passed on from generation to generation. This review has gone a long way toward integrating and enhancing our understanding of ornamental creativity as a possible sexual selected psychological trait.

A meta-analysis of sex differences in animal personality: no evidence for the greater male variability hypothesis

The notion that men are more variable than women has become embedded into scientific thinking. For mental traits like personality, greater male variability has been partly attributed to biology, underpinned by claims that there is generally greater variation among males than females in non-human animals due to stronger sexual selection on males. However, evidence for greater male variability is limited to morphological traits, and there is little information regarding sex differences in personality-like behaviours for non-human animals. Here, we meta-analysed sex differences in means and variances for over 2100 effects (204 studies) from 220 species (covering five broad taxonomic groups) across five personality traits: boldness, aggression, activity, sociality and exploration. We also tested if sexual size dimorphism, a proxy for sex-specific sexual selection, explains variation in the magnitude of sex differences in personality. We found no significant differences in personality between the sexes. In addition, sexual size dimorphism did not explain variation in the magnitude of the observed sex differences in the mean or variance in personality for any taxonomic group. In sum, we find no evidence for widespread sex differences in variability in non-human animal personality.

Neuroanatomical norms in the UK Biobank: The impact of allometric scaling, sex, and age

Few neuroimaging studies are sufficiently large to adequately describe population‐wide variations. This study's primary aim was to generate neuroanatomical norms and individual markers that consider age, sex, and brain size, from 629 cerebral measures in the UK Biobank (N = 40,028). The secondary aim was to examine the effects and interactions of sex, age, and brain allometry—the nonlinear scaling relationship between a region and brain size (e.g., total brain volume)—across cerebral measures. Allometry was a common property of brain volumes, thicknesses, and surface areas (83%) and was largely stable across age and sex. Sex differences occurred in 67% of cerebral measures (median |β| = .13): 37% of regions were larger in males and 30% in females. Brain measures (49%) generally decreased with age, although aging effects varied across regions and sexes. While models with an allometric or linear covariate adjustment for brain size yielded similar significant effects, omitting brain allometry influenced reported sex differences in variance. Finally, we contribute to the reproducibility of research on sex differences in the brain by replicating previous studies examining cerebral sex differences. This large‐scale study advances our understanding of age, sex, and brain allometry's impact on brain structure and provides data for future UK Biobank studies to identify the cerebral regions that covary with specific phenotypes, independently of sex, age, and brain size.

Gender Differences in the Distribution of Creativity Scores: Domain-Specific Patterns in Divergent Thinking and Creative Problem Solving

The present study examined gender differences in the distribution of creative abilities through the lens of the greater male variability hypothesis, which postulated that men showed greater interindividual variability than women in both physical and psychological attributes (Ellis, 1894/1934). Two hundred and six (51.9% female) undergraduate students in Hong Kong completed two creativity measures that evaluated different aspects of creativity, including: (a) a divergent thinking test that aimed to assess idea generation and (b) a creative problem-solving test that aimed to assess restructuring ability. The present findings extended the research of greater male variability in creativity by showing that men generally exhibited greater variance than women in the overall distribution of the creativity scores in both divergent thinking and creative problem solving, despite trivial gender differences in mean scores. The findings further enriched the discourse of the greater male variability hypothesis by showing interesting domain-specific gendered patterns: (1) greater male variability was more likely to occur in figural forms of creativity, with larger effect sizes, when compared to the variability in verbal forms of creativity; and (2) mixed gendered patterns were found in the upper tails of the creativity score distribution with respect to the verbal domain but not the figural one, despite greater male representation being consistently observed in the lower tail of the distribution. Possible underlying mechanisms and implications were discussed.

A 4-Year Longitudinal Study of the Sex-Creativity Relationship in Childhood, Adolescence, and Emerging Adulthood: Findings of Mean and Variability Analyses

The relationship between sex and creativity remains an unresolved research question. The present study aimed to approach this question through the lens of the developmental theory of sex differences in intelligence, which posits a dynamic pattern of sex differences in intellectual abilities from female superiority in childhood and early adolescence to male superiority starting at 16 years of age. A total of 775 participants from three age groups (i.e., children, adolescents, and emerging adults) completed a 4-year longitudinal study comprising four assessments of creative thinking at 1-year intervals. Creative thinking was assessed with the Test for Creative Thinking-Drawing Production. While the results revealed female superiority in childhood and early adolescence, male superiority was not found in adolescence and emerging adulthood. Rather, greater sex similarities and greater male variability were found based on mean and variability analyses, respectively. This study elucidated the link between sex and creativity by (1) taking a developmental perspective, (2) employing a 4-year longitudinal design in three age groups (i.e., children, adolescents, and emerging adults), and (3) analyzing sex differences based on both mean and variability analyses.

Individual differences in developmental plasticity: A role for early androgens?

Developmental plasticity is a widespread property of living organisms, but different individuals in the same species can vary greatly in how susceptible they are to environmental influences. In humans, research has sought to link variation in plasticity to physiological traits such as stress reactivity, exposure to prenatal stress-related hormones such as cortisol, and specific genes involved in major neurobiological pathways. However, the determinants of individual differences in plasticity are still poorly understood. Here we present the novel hypothesis that, in both sexes, higher exposure to androgens during prenatal and early postnatal life should lead to increased plasticity in traits that display greater male variability (i.e., a majority of physical and behavioral traits). First, we review evidence of greater phenotypic variation and higher susceptibility to environmental factors in males; we then consider evolutionary models that explain greater male variability and plasticity as a result of sexual selection. These empirical and theoretical strands converge on the hypothesis that androgens may promote developmental plasticity, at least for traits that show greater male variability. We discuss a number of potential mechanisms that may mediate this effect (including upregulation of neural plasticity), and address the question of whether androgen-induced plasticity is likely to be adaptive or maladaptive. We conclude by offering suggestions for future studies in this area, and considering some research designs that could be used to empirically test our hypothesis.