Sibling influences on gender development in middle childhood and early adolescence: a longitudinal study.

The development of gender role qualities (attitudes, personality, leisure activities) from middle childhood to early adolescence was studied to determine whether siblings' gender role qualities predicted those of their sisters and brothers. Participants were 198 firstborn and second-born siblings (Ms = 10 years 9 months and 8 years 3 months, respectively, in Year 1) and their parents. Families were interviewed annually for 3 years. Firstborn siblings' qualities in Year 1 predicted second-born children's qualities in Year 3 when both parent and child qualities in Year 1 were controlled, a pattern consistent with a social learning model of sibling influence. Parental influence was more evident and sibling influence less evident in predicting firstborns' qualities; for firstborns, sibling influences suggested a de-identification process.

Criteria for evaluating the significance of developmental research in the twenty-first century: force and counterforce.

Since its birth approximately 100 years ago, the field of child development has undergone fluctuations in the criteria used to determine which research topics are more or less worthy of study. The purpose of this paper is to identify the forces that influence how developmental research is prioritized and evaluated and how these influences are changing as we enter the new millennium. We do so by considering the developmental researcher in context and suggest that there will be increasing pressure to use new criteria when assessing the significance of twenty-first-century developmental science. We review the three most commonly used forms of research validity--internal, external, and ecological--and then identify new research validities that we believe are likely to play increasingly important roles in the next millennium. We also argue that many developmental scientists will increasingly be pressured by forces that are external to the traditional research environment and that these forces will shape the ways in which the significance of developmental research is evaluated.

Adolescents sex-typed friendship experiences: does having a sister versus a brother matter?

This study examines the connections between having a sister versus a brother and coming from a same-sex versus an opposite-sex sibling dyad and the degree of sex-typing in adolescents' friendship experiences, including the qualities of their friendships (i.e., intimacy, control) and their friends' personal attributes (i.e., sex-typed leisure interests, expressive and instrumental personality qualities). Participants were 159 firstborn-secondborn adolescent sibling pairs (M = 14.94 years and M = 12.43 years, respectively) and a close friend of each sibling (N = 636, including siblings and friends). Data were collected during home visits with siblings and telephone interviews with friends of siblings. The results suggested that sisters may learn control tactics from their brothers that they apply in their friendships; boys, however, were less likely to model the emotional intimacy that characterized their sisters' experiences with friends. In addition, coming from an opposite-sex sibling dyad was linked to sex-typing in friends' personal attributes, particularly their masculine leisure interests and instrumental personality qualities. Sisters and brothers may provide unique opportunities to learn about sex-typed relationship experiences in early adolescence, a time when gender segregation in the peer context is pervasive.

Congruence between mothers' and fathers' differential treatment of siblings: links with family relations and children's well-being.

We studied patterns of mothers' and fathers' differential treatment of firstborn (average age 10.5 years) and secondborn (average age 8 years) school-age siblings, and we examined the links between parents' differential treatment and children's well-being and dyadic family relationships. Mothers, fathers, and both siblings in 110 families were interviewed in their homes. For each dimension of parental behavior that we assessed (i.e., differential affection and discipline) we created groups of families that reflected mothers' and fathers' levels of differential treatment (e.g., discipline the firstborn more, equal treatment, discipline the secondborn more). Although we detected substantial correspondence between the 2 parents' differential treatment, we found a sizable group of families in which parents' reports were incongruent (i.e., 1 parent reported equal and the other differential treatment). Parental patterns were linked to differences between the siblings' well-being and both sibling and parent-child relationships, with younger siblings exhibiting greater vulnerability to differential treatment. Incongruence in differential warmth was associated with marital distress.