Male-male competition is involved in inter- and intrasexual selection, with both endocrine and psychological factors presumably contributing to reproductive success in human males. We examined relationships among men’s naturally occurring testosterone, their self-perceived mate value, self-esteem, sociosexuality, and expected likelihood of approaching attractive women versus situations leading to child involvement. We then monitored changes in these measures in male rowers from Cambridge, UK, following a manipulated “win” or “loss” as a result of an indoor rowing contest. Baseline results revealed that (...) men with heightened testosterone and SPMV values typically had greater inclinations toward engaging in casual sexual relationships and a higher likelihood of approaching attractive women in a hypothetical social situation. As anticipated, both testosterone and SPMV increased following a manipulated “victory” and were associated with heightened sociosexuality, and increased expectations toward approaching attractive women versus individuals who would involve them in interacting with children after the race. SPMV and self-esteem appeared to mediate some of the effects of testosterone on post-race values. These findings are considered in the broader context of individual trade-offs between mating and parental effort and a model of the concurrent and dynamic androgenic and psychological influences contributing to male reproductive effort and success. (shrink)

Adolescence signifies a transition from the use of prereproductive to reproductive strategies in the life history of Homo sapiens. Insofar as human generations overlap, events at adolescence, surrounding the onset of puberty, offer a unique glimpse into human adaptation from the point of view of the changing strategies of both parents and offspring. The timing of puberty is an important life history trait that varies between species, but also between and within the sexes in human beings. The onset of puberty (...) marks the beginning of the reproductive life, is affected by previous experience, and serves as a trigger for behavioral change. Surbey (1988, 1990) reported relationships between father absence, heightened levels of childhood stress, and early menarche and considered them within the context of human evolutionary history. Subsequently, similar findings have been reported in a number of human populations and have been interpreted from several evolutionary perspectives. This article discusses the extent to which these and related findings regarding alterations in the timing of human puberty reflect evolved parental or offspring strategies. It entails a consideration of the applicability of the concepts of phenotypic plasticity, nonadaptive genetic variation, and conditional and alternative reproductive strategies in describing the interwoven nature of strategies employed by parent and child in the transition at adolescence. (shrink)

Sexually dimorphic mate selection strategies were examined in 200 university students reporting their willingness to engage in casual sexual encounters with hypothetical individuals of the opposite sex. Using a questionnaire format, the possibility of forming a long-term relationship was manipulated, while risk of disease, pregnancy, and detection was eliminated across all conditions. In addition, potential partners varied in level of attractiveness, and in personality and behavioral characteristics. As expected, men reported a greater anticipated willingness to engage in sexual intercourse across (...) all conditions compared with women. The possibility of forming a long-term relationship elevated women’s, but not men’s, willingness for sexual intercourse. While a potential partner’s attractiveness had a significant positive overall effect on responses, reducing their relative attractiveness had a greater negative impact on men’s responses. Reference to the parental qualities of a potential partner significantly increased women’s, but not men’s, anticipated willingness for sexual intercourse. Describing a hypothetical partner as non-aggressive marginally increased women’s willingness and did not affect men’s responses. The wording of items relevant to this condition may have resulted in the potential partner sounding "wimpy" rather than nonaggressive, and this may have reduced the expected effect of this manipulation. The possibility that women may trade off personality and behavioral characteristics with attractiveness to a greater degree than men when assessing potential mates is considered. (shrink)