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O'Shea, K. J.

Publications and source records attributed to O'Shea, K. J..

2 recordsLinked to original sources

Facial masculinity is only weakly correlated with handgrip strength in young adult women

ObjectivesAncestrally, strength is likely to have played a critical role in determining the ability to obtain and retain resources and the allocation of social status among humans. Responses to facial cues of strength are therefore thought to play an important role in human social interaction. Although many researchers have proposed that sexually dimorphic facial morphology is reliably correlated with physical strength, evidence for this hypothesis is somewhat mixed. Moreover, to date, only one study has investigated the putative relationship between facial masculinity and physical strength in women. Consequently, we tested for correlations between handgrip strength and objective measures of face-shape masculinity.\n\nMethods531 women took part in the study. We measured each participants handgrip strength (dominant hand). Sexual dimorphism of face shape was objectively measured from each face photograph using two methods: discriminant analysis and vector analysis. These methods use shape components derived from principal component analyses of facial landmarks to measure the probability of the face being classified as male (discriminant analysis method) or to locate the face on a female-male continuum (vector analysis method).\n\nResultsOur analyses revealed that handgrip strength is, at best, only weakly correlated with facial masculinity in women. There was a weak significant association between handgrip strength and one measure of womens facial masculinity. The relationship between handgrip strength and our other measure of womens facial masculinity was not significant.\n\nDiscussionTogether, these results do not support the hypothesis that face-shape masculinity is an important cue of physical strength, at least in women.

animal behavior and cognition

Hormonal regulation of women’s prosocial, but not sexual, responses to kinship cues

Mate preferences and mating-related behaviors are hypothesized to change over the menstrual cycle in ways that function to increase reproductive fitness. Results of recent large-scale studies suggest that many of these hormone-linked behavioral changes are less robust than was previously thought. One hypothesis that has not yet been subject to a large-scale test is the proposal that womens preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle. Consequently, we used a longitudinal design to investigate the relationship between changes in womens steroid hormone levels and their perceptions of faces experimentally manipulated to possess kinship cues. Analyses suggested that women viewed mens faces displaying kinship cues more positively (i.e., more attractive and trustworthy) when estradiol-to-progesterone ratio was high. Since estradiol-to-progesterone ratio is positively associated with conception risk during the menstrual cycle, these results directly contradict the hypothesis that womens preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle. Data and code are publicly available at https://osf.io/wnhma/.

animal behavior and cognition