A greater decline in female facial attractiveness during middle age reflects women’s loss of reproductive value

Facial attractiveness represents an important component of an individual’s overall attractiveness as a potential mating partner. Perceptions of facial attractiveness are expected to vary with age-related changes in health, reproductive value, and power. In this study, we investigated perceptions of facial attractiveness, power, and personality in two groups of women of pre- and post-menopausal ages (35–50 years and 51–65 years, respectively) and two corresponding groups of men. We tested three hypotheses: (1) that perceived facial attractiveness would be lower for older than for younger men and women; (2) that the age-related reduction in facial attractiveness would be greater for women than for men; and (3) that for men, there would be a larger increase in perceived power at older ages. Eighty facial stimuli were rated by 60 (30 male, 30 female) middle-aged women and men using online surveys. Our three main hypotheses were supported by the data. Consistent with sex differences in mating strategies, the greater age-related decline in female facial attractiveness was driven by male respondents, while the greater age-related increase in male perceived power was driven by female respondents. In addition, we found evidence that some personality ratings were correlated with perceived attractiveness and power ratings. The results of this study are consistent with evolutionary theory and with previous research showing that faces can provide important information about characteristics that men and women value in a potential mating partner such as their health, reproductive value, and power or possession of resources

Ethnicity-Related Variation in Sexual Promiscuity, Relationship Status, and Testosterone Levels in Men

The purpose of this study was to investigate potential ethnicity-related variation in men's relationship status, sexual promiscuity, and testosterone levels. Data from two ethnically diverse subject populations were used. The first dataset included 302 male graduate students (age range: 23-36 years; M ϭ 28); the second dataset consisted of 77 male undergraduate and graduate students (age range: 18 -38 years; M ϭ 23). For both, we collected information on ethnicity (European American, African American, Hispanic, or Asian American), relationship status (single, in a short-term or long-term relationship, or married), and sexual promiscuity (number of lifetime sexual partners, number of one-night stands, extrapair sexual activity), in addition to measuring salivary testosterone concentrations. In both datasets testosterone levels were significantly higher in single men than in men in relationships but this difference was reversed in men of Asian American ethnicity. Asian American men had the lowest number of sexual partners, one-night stands, and extrapair sexual activity across ethnic groups. Moreover, among Asian Americans, men in relationships had a higher average number of sexual partners than single men. Our results indicate that to understand the association between relationship status and testosterone levels in men, ethnicity-related variation in sexual activity in single men and men in relationships must be taken into consideration

Relationship Status and Relationship Instability, but Not Dominance, Predict Individual Differences in Baseline Cortisol Levels

We investigated variation in baseline cortisol levels in relation to relationship status (single or in a relationship), relationship characteristics (length, stability, presence or absence of clear dominance), or individual attributes (dominant or subordinate status, relative physical attractiveness, relationship worries). Study participants were 77 men and 75 women aged between 18 and 38 years. Individuals in romantic relationships had lower cortisol levels than singles. Individuals of African ethnicity, however, showed the opposite pattern. Individuals who perceived their relationship to be highly unstable had higher cortisol levels. Aside from African-Americans, married individuals reported the lowest relationship instability and the lowest cortisol levels, followed by individuals in long-term relationships, and by individuals in short-term relationships. The presence or absence of clear dominance in the relationship, dominance status, or relationship worries did not affect cortisol levels. Therefore relationship status and relationship instability were better predictors of variation in cortisol (presumably through stress-related mechanisms) than individual attributes. </p

When Violence Pays: A Cost-Benefit Analysis of Aggressive Behavior in Animals and Humans

An optimization analysis of human behavior from a comparative perspective can improve our understanding of the adaptiveness of human nature. Intra-specific competition for resources provides the main selective pressure for the evolution of violent aggression toward conspecifics, and variation in the fitness benefits and costs of aggression can account for inter-specific and inter-individual differences in aggressiveness. When aggression reflects competition for resources, its benefits vary in relation to the characteristics of the resources (their intrinsic value, abundance, spatial distribution, and controllability) while its costs vary in relation to the characteristics of organisms and how they fight (which, in turn, affects the extent to which aggression entails risk of physical injury or death, energetic depletion, exposure to predation, psychological and physiological stress, or damage to social relationships). Humans are a highly aggressive species in comparison to other animals, probably as a result of an unusually high benefit-to-cost ratio for intra-specific aggression. This conclusion is supported by frequent and widespread occurrence of male-male coalitionary killing and by male-female sexual coercion. Sex differences in violent aggression in humans and other species probably evolved by sexual selection and reflect different optimal competitive strategies for males and females

Scores for the “Worrying about the relationship” scale in relation to dominance status within the relationship and gender.

<p>A low score indicates that the individual is more worried about the relationship than his/her partner; a high score indicates that the individuals thinks that his/her partner is more worried than himself/herself. </p

Cortisol levels in relation to ethnic group and relationship status.

<p>Sample sizes: Caucasians (single= 17; relationship= 45), Hispanics (single=8; relationship= 8), Asians (single=10; relationship= 13), Africans (single=8; relationship= 13). </p