It 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.

Under crowded conditions the friendly social interactions between members of a group become reduced, and the destructive and aggressive patterns show a marked rise in frequency and intensity.

Looking 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.

A true bond of friendship is usually only possible between people of roughly equal status. This equality is demonstrated in many indirect ways, but it is reinforced in face-to-face encounters by a matching of the posture of relaxation or alertness.

I viewed my fellow man not as a fallen angel, but as a risen ape.

Sexual 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.

The female covers her breasts, and then proceeds to redefine their shape with a brassiere. This sexual signaling device may be padded or inflatable, so that it not only reinstates the concealed shape, but also enlarges it, imitating in this way the breast swelling that occurs during sexual arousal.