Your Baby Becoming a Social Butterfly
At this age, your baby is a much more active participant, and even initiator, of interpersonal relationships with those around him. He can recognize and distinguish between the people who care for him, and begins to react specifically to each one, through laughter and other forms of communication.
Family and Friends versus Strangers
By about five months of age, your baby may stop smiling at unfamiliar faces. He may gaze at someone new quite seriously for a second, as if studying his or her features, and then burst out crying. The smile is now reserved for those he knows. These are the first signs of stranger anxiety. He is also now aware of how his actions cause reactions and, for example, expects you to smile back at him.
Exploring and Gaining Control
Baby begins to touch your face, exploring facial features, pulling hair, or sticking his fingers in your mouth – or his own. Through these actions he learns to distinguish between different sensations. Now that he can control his head movement he can regulate the degree of stimulation that he accepts. For instance, he will turn his head away when he becomes bored or if the stimulation is too intense.