Köhler found that a chimpanzee can imitate only those intelligent acts of other apes that it could have performed on its own. Persistent training, it is true, can induce it to perform much more complicated actions, but these are carried out mechanically and have all the earmarks of meaningless habits rather than of insightful solutions. The cleverest animal is incapable of intellectual development through imitation. It can be drilled to perform specific acts, but the new habits do not result in new general abilities.

Comparative psychology has identified a number of symptoms that may help to distinguish intelligent, conscious imitation from automatic copying. In the first case, the solution comes instantly in the form of insight not requiring repetition. Such a solution pertains to all characteristics of intellectual action. It involves understanding the field structure and relations between objects. On the contrary, drill imitation is carried out through repeating trail-and-error series, which show no sign of conscious comprehension and do not include understanding the field structure. In this sense, it can be said that animals are unteachable.

In the child’s development, on the contrary, imitation and instruction play a major role. They bring out the specifically human qualities of the mind and lead the child to new developmental levels. In learning to speak, as in learning school subjects, imitation is indispensable. What the child can do in cooperation today he can do alone tomorrow. Therefore the only good kind of instruction is that which marches ahead of development and leads it; it must be aimed not so much at the ripe as at the ripening functions.

– Lev Vygotsky, Thought and Language