SEX has probably been a commodity for as long as human society has existed, and perhaps even longer. The “oldest profession” seemingly has pre-human evolutionary roots. “When the opportunity arises, male macaque monkeys groom females to ‘pay’ for sex,” says Michael Gumert of Nanyang Technological University, Singapore.
Gumert looked at research on a 50-strong group of long-tailed macaques in Kalimantan Tengah, Indonesia, that covered a 20-month period. He found there was an increase in sexual activity after bouts of male-to-female grooming. On average, females had sex 1.5 times per hour, but immediately after being groomed by a male partner, this…
