"Does all this frivolous sex make our species sound "animalistic"? It shouldn't. The animal world is full of species that have sex only during widely spaced intervals when the female is ovulating. Only two species can do it week in and week out for nonreproductive reasons: one human, the other very humanlike. Sex for pleasure with various partners is therefore more "human" than animal. Strictly reproductive, once-in-a-blue-moon sex is more "animal" than human. In other words, an excessively horny monkey is acting "human," while a man or woman uninterested in sex more than once or twice a year would be, strictly speaking, "acting like an animal."