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Facial resemblance between women's partners and brothers
Tamsin Saxton et al.
Evolution and Human Behavior, forthcoming
Abstract:
Research on optimal outbreeding describes the greater reproductive success experienced on average by couples who are neither too closely related, nor too genetically dissimilar. How is optimal outbreeding achieved? Faces that subtly resemble family members could present useful cues to a potential reproductive partner with an optimal level of genetic dissimilarity. Here, we present the first empirical data that heterosexual women select partners who resemble their brothers. Raters ranked the facial similarity between a woman's male partner, and that woman's brother compared to foils. In a multilevel ordinal logistic regression that modeled variability in both the stimuli and the raters, there was clear evidence for perceptual similarity in facial photographs of a woman's partner and her brother. That is, although siblings themselves are sexually aversive, sibling resemblance is not. The affective responses of disgust and attraction may be calibrated to distinguish close kin from individuals with some genetic dissimilarity during partner choice.
Can Contraceptive Pill Affect Future Offspring’s Health? The Implications of Using Hormonal Birth Control for Human Evolution
Sheer Birnbaum, Gurit Birnbaum & Tsachi Ein-Dor
Evolutionary Psychological Science, June 2017, Pages 89–96
Abstract:
Resistance to disease is greater for offspring if the parents have dissimilar immune systems, as their pathogen-detection ability is enhanced. Accordingly, women evolved to be sexually attracted to men with a dissimilar immune system, primarily during high-fertility cycle phases. Contraceptive pills, however, reverse women’s preferences, leading them to be attracted to men with a similar immune system. In the present study (N = 192), we compared the health of children born to parents who met while the mother was on the pill with that of children whose parents met when the mother was not on the pill. Results confirmed our predictions, indicating that children to mothers who were on the pill are more infection-prone, require more medical care, suffer from a higher frequency of common sicknesses, and are perceived as generally less healthy than children whose parents met on non-pill circumstances. Results are discussed in light of the current antibiotic world crisis.
The effect of red color on perceived self-attractiveness
Anne Berthold, Gerhard Reese & Judith Martin
European Journal of Social Psychology, forthcoming
Abstract:
Recent research showed that individuals are perceived as more attractive when presented with the color red. We seek to extend these findings by studying the effects of red color on individuals' perception of self-attractiveness, rather than the attractiveness of others. Based on the color-in-context theory, we hypothesized that individuals would perceive themselves as more attractive under red chromatic conditions. In three experiments, participants were asked to wear a red or a blue shirt and rated their own attractiveness. As expected, participants in the red shirt condition indicated a higher level of self-attractiveness than participants in the blue condition. Moreover, the results showed that the self-perception red effect was mediated by the individuals' self-perceived sexual receptivity and self-perceived status.
Sexual Dimorphism in Waist-to-Hip Ratio and Divorce Frequency in Human Populations
Pilar Chiappa & Suneeta Singh
Evolutionary Behavioral Sciences, forthcoming
Abstract:
The current study tests a series of evolutionary predictions about the changing opportunities for human male mate choice and female Waist-to-Hip Ratio (WHR) across populations. We predicted that the divorce frequency (that we used as a reflection of the frequency of male mate choice) would be positively correlated with sexual dimorphism in WHRs across human populations. With published data, we built 2 samples, 1 at the international level and the other at the national level. The results showed that sexual dimorphism in WHR is positively correlated with the divorce-to-married ratio in 68 countries worldwide, as well as in the 32 Mexican states. Taken together, our results suggest that the opportunity for human male mate choice, based on female WHR, varies among human populations. We discuss the possibility of connecting this variation to human diversity in divorce practices. We conclude that human male mate choice is a circumstantially conditioned selective process responsible for such dimorphism and suggest that cultural and social aspects are potentially powerful in examining the factors capable of strengthening or weakening the selective process.