BASIC BOOKS, JUNE 2013Popular books have established the notion that human copulation has two unique features: It can take place at any time in the ovarian cycle, and it occurs even during pregnancy. On this basis, Desmond Morris described humans as the “sexiest” primate species. Yet both claims to uniqueness clash with abundant biological evidence.
We can quickly dismiss the claim that copulation during pregnancy is unique to humans. It is easy to understand how this myth originated. Copulation after conception seemingly serves no useful biological function, so it is tempting to assume that it never happens with other mammals. But it most certainly does. It is widespread in the animal kingdom, as has been known for more than a century. A rapid survey at once reveals that copulation during pregnancy has been seen in mammals as diverse as shrews, mice, hamsters, rabbits, pigs, cows, horses, and primates, including tamarins, macaques, baboons, sacred langurs, and chimpanzees. Hormonal patterns associated with mating during pregnancy have been studied in rhesus monkeys. Copulation during pregnancy in other mammals mainly occurs early on and ...
