As increasing emphasis is placed upon the importance of personality patterns in social, occupational, and personal relationships, the factors which influence personality development become more and more important in understanding and developing methods of dealing with personality variations in many different situations. Among the factors of thought to play an important part in the formation of personality, relationships among siblings have long been considered significant. Frequent reference is made in psychological literature to the effects upon personality of being an older child, a younger child, an only child, etc. Unfortunately most of these references have had little scientific evidence upon which to base their conclusions.
