There may be cases of imitation which cannot be thus accounted for as special instinctive responses to the perception of certain acts by the same acts, as habits formed under the condition that the satisfyingness of a response is its likeness to the perceived act of another, or as the connection of two habits, one of getting, from the perceived act of another, a certain inner condition, the other of getting, from this inner condition, the act in question. There may be, that is, cases where the perceived act of another in and of itself creates a connection. It is apparently taken for granted by a majority of writers on human behavior that cases of such direct mental infection, as it were, not only exist, but are the rule. I am unable to find proof of such cases, however. Those commonly quoted are far from clear. Learning to talk in the human infant, for example, the stock case of imitation as a direct means of learning, offers only very weak and dubious evidence. Since what is true of it holds substantially for the other favored cases for learning by imitation, I shall examine it at some length. Let us first be clear as to the alternative explanations of linguistic imitation. The first is that seeing the movements of another’s mouth-parts or hearing a series of word-sounds in and of itself produces the response of making that series of sounds or one like it. The other is that the laws of instinct and habit are adequate to explain the fact in the following manner: A child instinctively produces a great variety of sounds and sound-series. Some of these, accepted as equal to words by the child’s companions, are rewarded, so that the child learns by the law of effect to use them in certain situations to attain certain results. It is possible also that a child instinctively feels a special satisfaction at babbling when spoken to and a special satisfaction at finding the sound he makes like one that rings in the ears of memory and has meaning. The latter would be like the instinctive satisfaction apparently felt in constructing an object which is like some real object whose appearance and meaning he knows.