There are one hundred and ninety-three living species of monkeys and apes.

One of the strangest features of previous studies of naked-ape behaviour is that they have nearly always avoided the obvious. The earlier anthropologists rushed off to all kinds of unlikely corners of the world in order to unravel the basic truth about our nature, scattering to remote cultural back-waters so atypical and unsuccessful that they are nearly extinct. They then returned with startling facts about the bizarre mating customs, strange kinship systems, or weird ritual procedures of these tribes, and used this material as though it were of central importance to the behaviour of our species as a whole. The work done by these investigators was, of course, extremely interesting and most valuable in showing us what can happen when a group of naked apes becomes side-tracked into a cultural blind alley. It revealed just how far from the normal our behaviour patterns can stray without a complete social collapse. What it did not tell us was anything about the typical behaviour of typical naked apes. This can only be done by examining the common behaviour patterns that are shared by all the ordinary, successful members of the major cultures—the mainstream specimens who together represent the vast majority. Biologically, this is the only sound approach. Against this, the old-style anthropologist would have argued that his technologically simple tribal groups are nearer the heart of the matter than the members of advanced civilizations. I submit that this is not so. The simple tribal groups that are living today are not primitive, they are stultified. Truly primitive tribes have not existed for thousands of years. The naked ape is essentially an exploratory species and any society that has failed to advance has in some sense failed, ‘gone wrong’. Something has happened to it to hold it back, something that is working against the natural tendencies of the species to explore and investigate the world around it. The characteristics that the earlier anthropologists studied in these tribes may well be the very features that have interfered with the progress of the groups concerned. It is therefore dangerous to use this information as the basis for any general scheme of our behaviour as a species.