ABSTRACT
The chimpanzees manifest intelligent behaviour of the general kind familiar in human beings. Not all their intelligent acts are externally similar to human acts, but under well-chosen experimental conditions, the type of intelligent conduct can always be traced. At any rate, this remains true: Chimpanzees not only stand out against the rest of the animal world by several morphological and, in the narrower sense, physiological, characteristics, but they also show a type of behaviour which counts as specifically human. The lack of an invaluable technical aid (speech) and a great limitation of those very important components of thought, so-called "images", would thus constitute the causes that prevent the chimpanzee from attaining even the smallest beginnings of cultural development. In the field of the experiments carried out the insight of the chimpanzee shows itself to be principally determined by his optical apprehension of the situation.
