Earliest Social Stimulations and Responses

Since normal infants become able to perceive objects in the environment at about the same time and since all have the fundamental experiences basic to social behavior, a typical sequence of the development of social responses can be described. Some conditioned social responses have been reported during the first month of life. Infants of this age sometimes stop crying when someone speaks, when someone enters the room, or even at the sight of a human face. Although these reactions seem to be responses to the presence of people, caution is necessary in interpreting them in individual instances. Very young infants often stop crying when any stimulus arouses their attention. If something touches him, if any noise or movement occurs, or if he merely relieves his own discomfort by turning to a less cramped position, the same response may be made. Some responses of infants to persons, then, are really social, while in other cases the infant reacts to the person only as a mechanical agent.

By the second month, social responses to persons are more clearly distinguishable. At the age of two full months, many infants will turn the head and eyes toward the sound of a human voice. These responses, of course, do not develop because of any inner social tendency, but are evidences of learned behavior.

The Recognition of Facial and Vocal Expressions

During the first two months of postnatal life the infant's smile at the presence of another human being is not dependent upon the latter's facial expression or tone of voice. The young human is not yet able to differentiate such relatively simple things as smiling and angry facial expressions, or kind and scolding words and tone. If a person bends over the crib of a two-monthsold infant and has a "smiling countenance," the infant may smile in return. But if the adult has an angry expression, the infant also may smile. The, infant even at the age of three or four months probably is unable to differentiate kind and angry looks, tones or gestures, although exceptions occur. From the close of the fourth month, however, infants show distinct signs of differentiating expressions and by the fifth month may cry at the scolding voice and threatening gesture. The child by this time has developed his powers of attention and observation to such an extent that he can watch the face and note any changes in its details. He also is capable of discriminating differences in tone of voice. Perhaps even more important is the fact that he has now learned that kindly expressions typically accompany satisfying ministrations to his needs, while harsh ones imply neglect or even painful punishment. Before the end of the first year he has made a great deal of progress in understanding vocal and facial expressions.