‘It is no more in our power to love always than it was not to love at all.’ –La Bruyère
Darwin made a famous distinction between men’s and women’s mating strategies, between choosy, coy females and ardent, promiscuous males. […]
Yet, as also anticipated by both Darwin and Trivers, empirical studies of both non-humans and humans reveal extraordinary flexibility in mating and investment behavior, both within and between the sexes. Reproductive strategies are clearly not an invariant, species-specific characteristic, but rather facultative responses to individual- and population-level social and ecological circumstances, rendering conditional mating strategies optimal. […]
For example, across the ethnographic record, human societies can range from polyandrous to polygynous mating patterns, same-sex marriage can be institutionalized as with woman-to-woman unions in East Africa and men can spend considerable amounts of time and effort in beautifying themselves as in West Africa. […]
Until recently, the study of sex-differentiated reproductive behaviour has relied on the long-standing model of sexual selection developed by Trivers. This model links sex roles directly to the differential investment in young by males and females. In its simplest form, this model posits that because males invest less initially (in sperm), they have a higher potential reproductive rate (PRR) and benefit more from mating multiply than do females. As a consequence, selection typically would favour mate-seeking and competitive behaviour in males, and heavy investment in parental care in females. […]
Using data from eight Makushi communities of southern Guyana, characterized by varying adult sex ratios contingent on migration, we show that even within a single ethnic group, male mating effort varies in predictable ways with the ASR. At male-biased sex ratios, men’s and women’s investment in mating effort are indistinguishable; only when men are in the minority are they more inclined towards short-term, low investment relationships than women.
{ Royal Society Open Science | Continue reading }
Using new data from the United Kingdom’s Annual Population Survey, we find that […] marriage may help ease the causes of the mid-life dip in life satisfaction and that the benefits of marriage are unlikely to be short-lived. We explore friendship as a mechanism which could help explain a causal relationship between marriage and life satisfaction, and find that well-being effects of marriage are about twice as large for those whose spouse is also their best friend.
