James M. Sherlock

Variation in Women’s Preferences Regarding Male Facial Masculinity Is Better Explained by Genetic Differences Than by Previously Identified Context-Dependent Effects

Women’s preferences for masculine versus feminine male faces are highly variable. According to a dominant theory in evolutionary psychology, this variability results from adaptations that optimize preferences by calibrating them to certain contextual factors, including women’s self-perceived attractiveness, short- versus long-term relationship orientation, pathogen disgust sensitivity, and stage of the menstrual cycle. The theory does not account for the possible contribution of genetic variation on women’s facial masculinity preference. Using a large sample (N = 2,160) of identical and nonidentical female Finnish twins and their siblings, we showed that the proportion of variation in women’s preferences regarding male facial masculinity that was attributable to genetic variation (38%) dwarfed the variation due to the combined effect of contextual factors (< 1%). These findings cast doubt on the importance of these context-dependent effects and may suggest a need for refocusing in the field toward understanding the wide genetic variation in these preferences and how this variation relates to the evolution of sexual dimorphism in faces.

The quantitative genetics of disgust sensitivity.

[Correction Notice: An Erratum for this article was reported in Vol 16(1) of Emotion (see record 2015-57029-001). In the article, the name of author Joshua M. Tybur was misspelled as Joshua M. Tyber. All versions of this article have been corrected.] Response sensitivity to common disgust elicitors varies considerably among individuals. The sources of these individual differences are largely unknown. In the current study, we use a large sample of female identical and nonidentical twins (N = 1,041 individuals) and their siblings (N = 170) to estimate the proportion of variation due to genetic effects, the shared environment, and other (residual) sources across multiple domains of disgust sensitivity. We also investigate the genetic and environmental influences on the covariation between the different disgust domains. Twin modeling revealed that approximately half of the variation in pathogen, sexual, and moral disgust is due to genetic effects. An independent pathways twin model also revealed that sexual and pathogen disgust sensitivity were influenced by unique sources of genetic variation, while also being significantly affected by a general genetic factor underlying all 3 disgust domains. Moral disgust sensitivity, in contrast, did not exhibit domain-specific genetic variation. These findings are discussed in light of contemporary evolutionary approaches to disgust sensitivity.

Microbes and masculinity: does exposure to pathogenic cues alter women's preferences for male facial masculinity and beardedness?

Women’s preferences for men’s androgen dependent secondary sexual traits are proposed to be phenotypically plastic in response to exposure to pathogens and pathogen disgust. While previous studies report that masculinity in facial shape is more attractive to women who have recently been exposed to pathogenic cues and who are high in self-reported pathogen disgust, facial hair may reduce male attractiveness under conditions of high pathogens as beards are a possible breeding ground for disease carrying ectoparasites. In the present study, we test whether women’s preferences for beardedness and facial masculinity vary due to exposure to different pathogenic cues. Participants (N = 688, mean age + 1SD = 31.94 years, SD = 6.69, range = 18–67) rated the attractiveness of facial composite stimuli of men when they were clean-shaven or fully bearded. These stimuli were also manipulated in order to vary sexual dimorphism by ±50%. Ratings were conducted before and after exposure to one of four experimental treatments in which participants were primed to either high pathogens (e.g. infected cuts), ectoparasites (e.g. body lice), a mixture of pathogens and ectoparasites, or a control condition (e.g. innocuous liquids). Participants then completed the three-domain disgust scale measuring attitudes to moral, sexual and pathogen disgust. We predicted that women would prefer facial masculinity following exposure to pathogenic cues, but would show reduced preferences for facial hair following exposure to ectoparasites. Women preferred full beards over clean-shaven faces and masculinised over feminised faces. However, none of the experimental treatments influenced the direction of preferences for facial masculinity or beardedness. We also found no association between women’s self-reported pathogen disgust and their preferences for facial masculinity. However, there was a weak positive association between moral disgust scores and preferences for facial masculinity, which might reflect conservatism and preferences for gender typicality in faces. Women’s preferences for beards were positively associated with their pathogen disgust, which runs contrary to our predictions and may reflect preferences for high quality individuals who can withstand any costs of beardedness, although further replications are necessary before firm conclusions can be made. We conclude that there is little support for pathogenic exposure being a mechanism that underpins women’s directional preferences for masculine traits.

Longitudinal Relationships Between Parents’ and Children’s Behavior Need Not Implicate the Influence of Parental Behavior and May Reflect Genetics: Comment on Waldinger and Schulz (2016)

Waldinger and Schulz (2016) provided evidence that individual differences in warmth of the parent-offspring relationship during adolescence are associated with the quality of the offspring’s romantic attachments 60 years later. Although the reported association was only a longitudinal correlation, Waldinger and Schulz interpreted it in causal terms: For example, they stated, “This study captured the long reach of warm parent-child relationships and nurturing family environment in shaping key aspects of functioning later in life” (p. 1449) and “The findings underscore the far-reaching influence of childhood environment on well-being in adulthood” (p. 1443). Unfortunately, genetic influences on attachment styles throughout the life span create a confound in such studies that calls into question causal interpretations. Indeed, similar errors are common in the broader literature on the effects of parenting (as we discuss later). Causal inferences about parental environment must be backed by appropriate evidence, and, at the very least, the possibility of genetic confounding should be discussed to avoid misleading other scientists and the media.

The link between deprivation and its behavioural constellation is confounded by genetic factors

Most research cited throughout Pepper & Nettles (P&Ns) target article is correlational and suffers from a serious genetic confound that renders it of little evidentiary value. Of correlational findings that are not confounded, P&N ignore examples that contradict their model. Further, P&Ns claim that evolutionary models explaining between-species differences in behaviour can be used to understand that corresponding individual differences lack any evidence.