How Sexual Promiscuity Lost Its Evolutionary Luster

There was a time when violence and hierarchy determined who was sleeping with who, but that was before women collectively decided that security was preferable to fertility. 

What's the Latest Development?

A new theory is forming to help explain why human relationships evolved from promoting sexual promiscuity to today's pair-bonding. Long ago, when violence and hierarchy determined who slept with who, females were naturally more promiscuous, habitually taking on more men than today's domesticated partnerships allow. University of Tennessee-Knoxville professor Sergey Gavrilets argues that the rise of pair-bonding "occurred only when lesser male hominids, realizing their physical inferiority, adopted a 'provider' role in partnerships, and female hominids, in turn, began to show fidelity to these partners."

What's the Big Idea?

Scientists have long debated the origins of pair-bonding because, according to evolutionary logic in which life tends to prefer greater genetic diversity and higher fertility, it never should have occurred. But females may have been instrumental in this change, choosing to prefer the security of a provider mate over the risk of lower fertility. "Critically, Gavrilets notes, this process begins with the weakest males...because they stand to gain the most from an alternative strategy like provisioning. Slowly, the strategy works its way up the dominance hierarchy, as females begin to reward the weaker males with their fidelity. Out of this sexual revolution comes self-domestication."

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