Child-Spacing Effects on Intelligence, Personality, and Social Competence

Summary

The effect of child spacing and family size on intelligence, personality, and social competence were studied in 533 suburban, middle class children in large (five or more) and small (two-child) families. Spacing was measured as to the next oldest sibling (Space-Old) and to the next youngest (Space-Young). Spacing measures were trichotomized into three categories: close (18 months or less), medium (19 to 30 months), and distant (more than 30 months). Standardized intelligence scores, the Test of Effective Academic Motivation, the Cattell High School Personality Questionnaire, questions about their participation in clubs, level of occupational aspiration, job orientation, and other personality scales were used. In corroboration with the Zajonc and Marcus model, the more closely spaced younger child was found to be less intelligent. However, these closely spaced children were also found to belong to more athletic teams, to be more interested in getting a job, and to be more ambitious occupationally. These closely spaced children tended to be more self-sufficient, more sober and serious, and more relaxed about protocol than were those children with a greater distance from their next oldest sibling. Most of these findings were significant only for large family children, spacing having less effect in children from two-child families.