EARLY PROXIMITY AND INTIMACY BETWEEN SIBLINGS AND INCESTUOUS BEHAVIOR - A TEST OF THE WESTERMARCK THEORY

This study was based on the Westermarck hypothesis, which maintains that the proximate mechanism for sibling incest avoidance is continued proximity in early childhood. Using a survey method, we compared university students reporting sibling incest with a matched sample of those reporting no such experiences on measures of both early intimacy of the sibling pair (e.g., sleeping arrangements, practices regarding nudity) and early separations between them. Intimacy variables did not relate to incestuous behavior. Separation for more than a year during the first six years was significantly related to sexual activities which culminated in anal, oral, or attempted or actual genital intercourse (labeled consummatory behaviors), but this difference in regard to nonconsummatory sexual activities was in the opposite direction. It was suggested that previous interpretations of the Westermarck effect implying that early cohabitation produces sexual disinterest may require revision. Early association may function instead to provide a barrier to more mature, consummatory sexual activities and, hence, reduce procreative potential.