Fatherhood, pairbonding and testosterone in the Philippines
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- 作者：Christopher W. Kuzawa ; Lee T. Gettler ; Martin N. Muller ; Thomas W. McDade ; Alan B. Feranil
- 关键词：Reproductive ecology ; Challenge hypothesis ; Steroids ; Paternal care ; Parenting effort ; Evolution ; Anthropology ; Child care ; Luteinizing hormone ; Salivary assays
- 刊名：Hormones and Behavior
- 出版年：2009
- 出版时间：October 2009
- 年：2009
- 卷：56
- 期：4
- 页码：429-435
- 全文大小：318 K
文摘
In species with a high level of paternal care, including humans, testosterone (T) is believed to help mediate the trade-off between parenting and mating effort. This hypothesis is supported by the observation of lower T in pairbonded men or fathers compared to single, non-fathers; however, prior work has highlighted population variation in the association between T and pairbonding or fatherhood status. Here we evaluate this hypothesis in a large (n = 890), representative birth cohort of young men (age range 20.5–22.5 years) living in Cebu City, the Philippines. Bioavailable T was measured in saliva collected prior to bed and immediately upon waking the following morning. Plasma T and luteinizing hormone (LH) were measured in morning plasma samples. In this sample, 20 % of men were pairbonded, defined as living with a partner or married, 13 % were fathers, and roughly half of fathers reported involvement in childcare. Pairbonded men had significantly lower T at both times of day. Unlike in other populations, this relationship was accounted for entirely by fatherhood status: among the large sub-sample of non-fathers, mean T was nearly identical among pairbonded and single men. There was a strong association between self-reported involvement in childcare and lower evening T, supporting the idea that the evening nadir in T is related to social interactions across the day. Similar relationships were found for total plasma T and LH, suggesting that these relationships are coordinated by centrally-mediated changes in LH secretion. The relatively modest T difference in relation to fatherhood at Cebu, in comparison to other studies, may reflect a lower level of paternal involvement in childcare activities in this population. Our findings using a large, well-characterized birth cohort support the hypothesized role of T as a mediator of mating and parenting effort in humans, while contributing evidence for cultural variation in the relative importance of pairbonding and fathering to these relationships.