Selling sex is said to be humankind’s oldest profession but it may have deep evolutionary roots, according to a study into our primate cousins which found that male macaques pay for intercourse by using grooming as a currency.
Michael Gumert of Nanyang Technological University in Singapore made the discovery in a 20-month investigation into 50 long-tailed macaques in Kalimantan Tengah, Indonesia, New Scientist reports on Saturday.
On average, females had sex 1.5 times per hour.
But this rate jumped to 3.5 times per hour immediately after the female had been groomed by a male — and her partner of choice was likely to be the hunky monkey that did the grooming.
Market forces also acted on the value of the transaction.
If there were several females in the area, the cost of buying sex would drop dramatically — a male could “buy” a female for just eight minutes of nit-picking.
But if there were no females around, he would have to groom for up to 16 minutes before sex was offered.
Hat Tip: Club for Growth