The child has usually begun to show signs of pleasure and displeasure long before he has reached six months. This phase of development may be indicated by his playing longer and more persistently with one toy than with any other. It may be shown by much more animated activity when certain familiar individuals are present than would be evidenced in the presence of others equally well known. Very frequently children at this age indulge in amused laughing aloud when bounced on the bed, or when some well-known individual indulges in strenuous exercises accompanied by vociferous exclamations while the baby is watching. ONE YEAR By the time a child has become twelve months old it will be possible to teach it many little tricks and movements of a simple nature. The child seems to imitate almost spontaneously the actions which are often repeated by its parents or nurse. Six to twelve trials should be sufficient to teach the average infant of one year how to “wave bye-bye” when told to do so, or how to hold its hands above its head when asked “How big are you?” or to hide its face behind its hands or behind one of its covers when someone exclaims “Peek-a-boo.” Some children never learn to creep before learning to walk. As a matter of fact, it seems fairly certain that the child who creeps rapidly may thereby postpone learning to walk. At the age of one year a child should be able to stand beside a chair without other assistance than the support given by the chair, or it should be able to creep very rapidly toward its toys or any other desired objects. Frequently, of course, children have learned to walk fairly well by the time they have attained twelve months, but this is rather unusual and is not particularly an indication of the degree of mental capacity. The child of one year understands many common words applying to frequently observed objects which have been repeatedly called to his attention. When asked “Where is the dog?—where is the ball?—where are the flowers?” and such questions the average infant will turn its head and look toward the object mentioned, sometimes pointing, although this is somewhat unusual. Simple commands such as “Lie down! No-no! Spit it out!” and the like, can be understood and are usually obeyed by children of this age. The speech of a child at this age is of course very simple, consisting of one syllable words, usually repeated. Such expressions as “ma-ma,” “bye-bye,” “da-da,” “go-go,” may be expected in the average child. It is unusual for an infant to combine two such expressions into a crude sentence at this age.