James R. Roney

Reading men's faces: women's mate attractiveness judgments track men's testosterone and interest in infants

This study investigated whether women track possible cues of paternal and genetic quality in mens faces and then map perception of those cues onto mate attractiveness judgments. Mens testosterone concentrations served as a proxy for genetic quality given evidence that this hormone signals immunocompetence, and mens scores on an interest in infants test were chosen as prima facie markers of paternal quality. Womens perceptions of facial photographs of these men were in fact sensitive to these two variables: mens scores on the interest in infants test significantly predicted womens ratings of the photos for how much the men like children, and mens testosterone concentrations significantly predicted womens ratings of the mens faces for masculinity. Furthermore, mens actual and perceived affinity for children predicted womens long-term mate attractiveness judgments, while mens testosterone and perceived masculinity predicted womens short-term mate attractiveness judgments. These results suggest that women can detect facial cues of mens hormone concentrations and affinity for children, and that women use perception of these cues to form mate attractiveness judgments.

Behavioral and hormonal responses of men to brief interactions with women

This study tested for behavioral and hormonal reactions of young men to brief social encounters with potential mating partners. Male college students were randomly assigned to engage in a short conversation with either a young man (male condition) or a young woman (female condition). Participants provided saliva samples before and after the conversation, completed a battery of psychological measures after the interaction, and had their behavior rated by their conversation partners. Salivary testosterone (T) increased significantly over baseline levels in the female condition only, though differences between conditions were not significant. In addition, change in T was significantly correlated with the degree to which the female confederates thought the male participants were trying to impress them. These behavioral ratings, in turn, were correlated with the participants’ ratings of the female confederates as potential romantic partners. Results were generally consistent with the hypothesis that human males may exhibit a behavioral and endocrine courtship response that is similar to that observed in males of many nonhuman vertebrate species.

Women's estradiol predicts preference for facial cues of men's testosterone

A growing body of research has shown that women express stronger attraction to more masculine traits when they are tested near ovulation than when tested during other times in the menstrual cycle. Although these effects have been interpreted as increased preferences for markers of elevated testosterone during times in the cycle when conception is most likely, no previous studies have directly demonstrated that women express stronger attraction to higher testosterone men at different times in the cycle. In addition, little research has addressed which hormonal or other physiological mechanisms may regulate temporal shifts in womens attractiveness judgments. In this research, we demonstrate that women with higher estradiol concentrations exhibit stronger preferences for the faces of men with higher testosterone concentrations, and that womens testosterone preference and estradiol curves track one another across days of the cycle. The findings are the first direct demonstration in humans that hormone concentrations in one sex are associated with attraction to cues of hormonal status in the opposite sex. The results support a functional role for estradiol in calibrating womens mating psychology to indices of their current fertility, analogous to similar processes that have been documented in nonhuman species. A strong correlation between estradiol and testosterone preference specifically during the luteal phase further suggests that womens mate preferences may track their fertility between different cycles in addition to being calibrated to the timing of ovulation within individual cycles.

Hormonal predictors of sexual motivation in natural menstrual cycles.

Little is known regarding which hormonal signals may best predict within- and between-women variance in sexual motivation among naturally cycling women. To address this, we collected daily saliva samples across 1-2 menstrual cycles from a sample of young women; assayed samples for estradiol, progesterone, and testosterone; and also collected daily diary reports of womens sexual behavior and subjective sexual desire. With respect to within-cycle, day-to-day fluctuations in subjective desire, we found evidence for positive effects of estradiol and negative effects of progesterone. Desire exhibited a mid-cycle peak, similar to previous findings; measured progesterone concentrations statistically mediated the fall in desire from mid-cycle to the luteal phase, but no combination of hormone measures substantially mediated the follicular phase rise in desire, which suggests that other signals may be implicated in this effect. Hormonal predictors of within-cycle fluctuations in sexual behavior generally reached only trend levels of statistical significance, though the patterns again suggested positive effects of estradiol and negative effects of progesterone. Between-women and within-women, between-cycle effects of hormone concentrations were generally absent, although statistical power was more limited at these higher levels of analysis. There were no significant effects of testosterone concentrations when controlling for the effects of estradiol and progesterone, which raises questions regarding the importance of this hormone for the regulation of sexual motivation in natural cycles. Our study is among the first to identify hormonal predictors of within-cycle fluctuations in sexual motivation, and thus adds novel evidence regarding the endocrine correlates of human sexuality.

Effects of Visual Exposure to the Opposite Sex: Cognitive Aspects of Mate Attraction in Human Males

This research is an investigation into the cognitive aspects of mate attraction in human males. Two experiments demonstrate that visual exposure to women (in person or within photographs) can prime large changes in the attitudes, mood states, and personality trait descriptions of male participants. These changes, furthermore, are such that participants show greater conformity to female mate preferences as described in the extant literature: In particular, men exposed to potential mates reported higher valuations of material wealth, greater momentary feelings of ambition, higher valuations of other indicators of social status, and personality trait descriptions indicative of high surgency/extraversion. All such effects occurred without participants’ awareness that their responses had been affected by the experimental manipulations. These findings suggest a model of mate attraction mechanisms in which input cues from potential mates can prime those psychological representations that facilitate the behavioral expression of courtship tactics.

The Origins of Extraversion: Joint Effects of Facultative Calibration and Genetic Polymorphism

The origins of variation in extraversion are largely mysterious. Recent theories and some findings suggest that personality variation can be orchestrated by specific genetic polymorphisms. Few studies, however, have examined an alternative hypothesis that personality traits are facultatively calibrated to variations in other phenotypic features, and none have considered how these distinct processes may interact in personality determination. Since physical strength and physical attractiveness likely predicted the reproductive payoffs of extraverted behavioral strategies over most of human history, it was theorized that extraversion is calibrated to variation in these characteristics. Confirming these predicted patterns, strength and attractiveness together explained a surprisingly large fraction of variance in extraversion across two studies— effects that were independent of variance explained by an androgen receptor gene polymorphism. These novel findings initially support an integrative model wherein facultative calibration and specific genetic polymorphisms operate in concert to determine personality variation.

Relative digit lengths and testosterone levels in Guinea baboons.

A growing body of literature suggests that the ratio of the lengths of the second to fourth digits (2D:4D) on human hands is sexually dimorphic and associated with prenatal exposure to gonadal hormones, circulating serum testosterone, and a number of psychological and behavioral measures. Little research has investigated digit ratios in nonhuman species. In the present study, we investigated sex differences in digit ratios and their possible association with serum testosterone in a captive group of Guinea baboons (Papio papio). Contrary to the sex difference typically reported in humans, male baboons exhibited a substantially larger 2D:4D than did female baboons. Consistent with the human data, however, lower 2D:4D was associated with higher serum testosterone among the males. The present findings suggest that the relationship between digit ratios and male gonadal hormones may be phylogenetically well-conserved, although they also suggest possible species differences in the causal relationships between developmental mechanisms and sex-differentiated digit length patterns.

Changes in estradiol predict within-women shifts in attraction to facial cues of men's testosterone

Many studies have demonstrated that women express stronger attraction to androgen-related traits when tested near ovulation than when tested at other times in the cycle. Much less research, however, has directly addressed which hormonal or other physiological signals may regulate these temporal shifts in womens attractiveness judgments. In the present study, we measured womens preferences for facial cues of mens testosterone concentrations on two occasions spaced two weeks apart, while also measuring womens salivary estradiol and testosterone concentrations at each testing session. Changes in womens estradiol concentrations across sessions positively predicted changes in their preferences for facial cues of high testosterone; there was no such effect for changes in womens testosterone concentrations. For the subset of women who had a testing session fall within the estimated fertile window, preferences for high testosterone faces were stronger in the fertile window session, and change in estradiol from outside to inside the fertile window positively predicted the magnitude of the ovulatory preference shift. These patterns were not replicated when testing preferences for faces that were rated as high in masculinity, suggesting that facial cues of high testosterone can be distinguished from the cues used to subjectively judge facial masculinity. Our findings suggest that womens estradiol promotes attraction to androgen-dependent cues in men (similar to its effects in females of various nonhuman species), and support a role for this hormone as a physiological regulator of cycle phase shifts in mating psychology.

Androgen receptor gene sequence and basal cortisol concentrations predict men's hormonal responses to potential mates

Exposure to potential mates triggers rapid elevations of testosterone and glucocorticoid concentrations in males of many non-human species, and preliminary studies support similar effects in human males. The human studies have all reported large individual differences in these responses, however, and the present study tested whether specific biological variables may help explain these differences. Replicating past research, the present study found that mens salivary testosterone and cortisol concentrations increased after a brief conversation with a young woman, but did not change (or slightly decreased) after a conversation with a young man. In addition, smaller numbers of CAG repeats in mens androgen receptor gene, and lower baseline cortisol concentrations, each predicted larger testosterone responses to the interactions with women. The CAG repeat finding demonstrates that a specific genetic polymorphism predicts physiological responses to social interactions that may in turn have important downstream consequences on mens mating behaviour. The effects of cortisol are consistent with past demonstrations of glucocorticoid inhibition of testosterone production and show that such inhibition also affects testosterone responses to social stimuli. In sum, the present study both confirms mens hormonal reactions to potential mates and identifies novel biological variables that predict individual differences in these responses.

RELATIVE DIGIT LENGTHS PREDICT MEN'S BEHAVIOR AND ATTRACTIVENESS DURING SOCIAL INTERACTIONS WITH WOMEN

Recent evidence suggests that the ratio of the lengths of the second and fourth fingers (2D:4D) may reflect degree of prenatal androgen exposure in humans. In the present study, we tested the hypotheses that 2D:4D would be associated with ratings of men’s attractiveness and with levels of behavioral displays during social interactions with potential mates. Our results confirm that male 2D:4D was significantly negatively correlated with women’s ratings of men’s physical attractiveness and levels of courtship-like behavior during a brief conversation. These findings provide novel evidence for the organizational effects of hormones on human male attractiveness and social behavior.