This brief report summarizes the findings and conclusions of studies concerning the relation between birth order and various aspects of personality and intellectual development. Major topics discussed are the relation between birth order of the child and: (1) the effects of sex and spacing between siblings on personality characteristics of the child (self-confidence, aggressiveness, criticalness, jealousy, etc.); (2) parents' expectations of the child and amount of attention shown to the child; (3) the degree of anxiety shown in dangerous or unfamiliar situations, the degree of risk-taking behavior, and the degree of conformity; (4) masculinity and femininity; (5) popularity among peers; (6) family size and intelligence. The pamphlet also mentions a possible bias in some birth-order research due to the high percentage of firstborn children in the population compared to children in other ordinal positions. (SS)