What effect does the child's position in the family have upon his social development? Some investigators hold that the conditions surrounding the oldest child in a family are most favorable to his social development so long as he is the only child, but that after a brother or sister is born his position is more difficult. The youngest one is supposed always to be the spoiled child, whereas the conditions surrounding the middle child (or children) are described as least favorable to social development. The accumulating mass of evidence, however, seems to show that this problem is very complex and not to be settled by an invariable formula. The oldest, youngest, and middle children undoubtedly have problems of social adjustment caused by their position in the family circle. Each one meets stimuli varying according to his age, sex, order of birth, and the changed attitudes of parents caused by changes in their financial status, as well as by changes in their age, physical condition, and interests. Changes in the conditions surrounding parents may alter their ways of disciplining and training their offspring.
In the poorest social surroundings, the only child did better school work than did children who had brothers or sisters, but children from homes of average socialeconomic status did better school work if they had one or two brothers or sisters. Some studies seem to show that only children do better school work, but that they may be more prone to nervousness, timidity, talkativeness, and dictatorial and anti-social behavior, and that they are not so popular with other children. Those with brothers and sisters are sometimes believed to be happier and gayer than only children. We cannot take all of these results at face value, however, because studies of American children show that the only child probably is superior to those having brothers or sisters and is not more inclined to sadness, nervousness, and the like. On the whole, we are inclined to believe that the child's position among brothers and sisters is of far less significance for his social development than many other family conditions, such, for example, as having but one parent or being a foster child, a step-child, or an illegitimate child. The character of the parents and the kind of training they provide are powerful forces shaping the child's social development, especially those features which usually are characterized as morality.