This paper investigates relationships between men’s testosterone and family life in a sample of approximately 350 Jamaican fathers of children 18–24 months of age. The study recognizes the role of testosterone as a proximate mechanism coordinating and reflecting male life history allocations within specific family and cultural contexts. A sample of Jamaican fathers and/or father figures reported to an assessment center for an interview based on a standardized questionnaire and provided a saliva sample for measuring testosterone level. Outcomes measured include (...) subject demographics such as age and relationship status as well as partnership quality and sexuality and paternal attitudes and behavior. The variation in these fathers’ relationship status was not associated with men’s testosterone. Too few stepfathers participated to enable a direct test of the prediction that stepfathers would have higher testosterone than biological fathers, although fathers who reported living with partners’ children did not have higher testosterone than fathers not reporting residing with a non-biological child. Fathers’ relationship quality was negatively related to their testosterone. Measures of paternal attitudes and behavior were not related to fathers’ testosterone. Consistent with previous ethnography, this sample of Jamaican fathers exhibited variable life history profiles, including residential status. We discuss why fathers’ relationship quality was found to be negatively related to their testosterone level, but other predictions were not upheld. (shrink)

Previous research in North America has supported the view that male involvement in committed, romantic relationships is associated with lower testosterone (T) levels. Here, we test the prediction that undergraduate men involved in committed, romantic relationships (paired) will have lower T levels than men not involved in such relationships (unpaired). Further, we also test whether these differences are more apparent in samples collected later, rather than earlier, in the day. For this study, 107 undergraduate men filled out a questionnaire and (...) collected one saliva sample (from which a subject’s T level was measured) at various times across the day. As in previous studies, men involved in committed, romantic relationships had lower salivary T levels, though only during later times of the day. Furthermore, additional analysis of the variation among unpaired subjects indicated that men without prior relationship experience had lower T levels than experienced men. Finally, while paired men as a group had lower T levels than unpaired men, those men at the earliest stage (less than six months) of a current relationship had higher T levels than unpaired men as well as men in longer-term relationships. These results suggest that variation in male testosterone levels may reflect differential behavioral allocation to mating effort. (shrink)

A large body of research links testosterone and cortisol to male-male competition. Yet, little work has explored acute steroid hormone responses to coalitional, physical competition during middle childhood. Here, we investigate testosterone, dehydroepiandrosterone, androstenedione, and cortisol release among ethnically Chinese boys in Hong Kong, aged 8–11 years, during a soccer match and an intrasquad soccer scrimmage, with 63 participants competing in both treatments. The soccer match and intrasquad soccer scrimmage represented out-group and in-group treatments, respectively. Results revealed that testosterone showed (...) no measurable change. DHEA increased during both treatments in the majority of participants and the degree of change had no relation to independent variables or covariate measures. Most boys experienced androstenedione increases during match play, but no significant differences during the intrasquad soccer scrimmage competitions. The magnitude of change differed significantly between treatments and was positively associated with age. These latter findings suggest boys’ androstenedione responses may be sensitive to competitor type. For most subjects, cortisol significantly increased during match play, decreased during the intrasquad soccer scrimmage, and differed significantly between treatments, suggesting each treatment promoted a different psychological state among competitors. Cortisol/DHEA molar ratio decreased during the intrasquad scrimmage, suggestive of a more relaxed mental state. These data shed new light on potential proximate mechanisms associated with coalitional competition among prepubescent boys, with relevance to adrenarche and life history theory. (shrink)

The ratio of index- and ring-finger lengths is thought to be related to prenatal androgen exposure, and in many, though not all, populations, men have a lower average digit ratio than do women. In many studies an inverse relationship has been observed, among both men and women, between 2D:4D ratio and measures of athletic ability. It has been further suggested that, in hunter-gatherer populations, 2D:4D ratio might also be negatively correlated with hunting ability, itself assumed to be contingent on athleticism. (...) This hypothesis has been tested using endurance running performance among runners from a Western, educated, and industrialized population as a proximate measure of hunting ability. However, it has not previously been tested among actual hunter-gatherers using more ecologically valid measures of hunting ability and success. The current study addresses this question among Tanzanian Hadza hunter-gatherers. I employ a novel method of assessing hunting reputation that, unlike previous methods, allows granular distinctions to be made between hunters at all levels of perceived ability. I find no statistically significant relationship between digit ratio and either hunting reputation or two important hunting skills. I confirm that Hadza men have higher mean 2D:4D ratios than men in many Western populations. I discuss the notion that 2D:4D ratio may be the consequence of an allometric scaling relationship between relative and absolute finger lengths. Although it is difficult to draw clear conclusions from these results, the current study provides no support for the theorized relationship between 2D:4D ratio and hunting skill. (shrink)