It must be stressed that there is nothing insulting about looking at people as animals. We are animals, after all. Homo sapiens is a species of primate, a biological phenomenon dominated by biological rules, like any other species. Human nature is no more than one particular kind of animal nature. Agreed, the human species is an extraordinary animal; but all other species are also extraordinary animals, each in their own way, and the scientific man-watcher can bring many fresh insights to the study of human affairs if he can retain this basic attitude of evolutionary humility.
Desmond MorrisLooking back now on the whole sexual scene we can see that our species has remained much more loyal to its basic biological urges than we might at first imagine. Its primate sexual system with carnivore modifications has survived all the fantastic technological advances remarkably well.
Desmond MorrisIt is interesting that amongst children of preschool age, the more intelligent ones tend to sleep less than the dull ones. After the age of seven this relationship is reversed, the more intelligent schoolchildren sleeping more than the dull ones.
Desmond MorrisSexual behavior in our species goes through three characteristic phases: pair formation, precopulatory activity, and copulation, usually but not always in that order. The pair-formation stage, usually referred to as courtship, is remarkably prolonged by animal standards.
Desmond Morris