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

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

Autistic-like and schizotypal traits in a life history perspective: diametrical associations with impulsivity, sensation seeking, and sociosexual behavior

According to recent theoretical models, autistic-like and schizotypal traits can be regarded as opposite sides of a single continuum of variation in personality and cognition, and may be diametrically associated with individual differences in life history strategies. In this view, schizotypy is a psychological phenotype oriented toward high mating effort and reduced parenting, consistent with a fast life history strategy, whereas autistic-like traits contribute to a slow strategy characterized by reduced mating effort and high parental investment. In this study, we tested the hypothesis that autistic-like and schizotypal traits would be diametrically associated with unrestricted sociosexuality, impulsivity, and sensation seeking (three key behavioral correlates of fast life history strategies in humans) in a sample of 152 young adults (18-38 years). The results were consistent with a diametrical autismschizotypy axis of individual variation. In line with our hypotheses, autism-schizotypy scores were uniquely associated with individual differences in impulsivity, sensation seeking, and sociosexual behavior, even after controlling for variation in Big Five personality traits. However, we found no significant associations with sociosexual attitude in the present sample. Our findings provide additional support for a life history model of autistic-like and schizotypal traits and demonstrate the heuristic value of this approach in the study of personality and psychopathology

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

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

(a) Relationship instability in relation to ethnic status.

<p>The higher the score the more unstable the relationships. (b) Relationship instability among individuals who are in short-term relationships, in long-term relationship, or married. Data from all four ethnic groups are combined.</p

(a). Cortisol levels in individuals who are single (n= 35), in short-term relationships (n= 17), in long-term relationships (n= 38), or married (n= 11). Data are pooled for Caucasians, Hispanics, and Asians. (b) Cortisol levels in African individuals who are single (n= 8), in short-term relationships (n= 5), or in long-term relationships (n= 9).

<p>(a). Cortisol levels in individuals who are single (n= 35), in short-term relationships (n= 17), in long-term relationships (n= 38), or married (n= 11). Data are pooled for Caucasians, Hispanics, and Asians. (b) Cortisol levels in African individuals who are single (n= 8), in short-term relationships (n= 5), or in long-term relationships (n= 9).</p

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