Child Temperaments, Maternal Differential Behavior, and Sibling Relationships

The primary purpose of this study was to examine the influence of two nonshared family environmental components-maternal differential behavior and sibling temperaments-on the sibling relationships of school-age children. Forty mothers and their same-sex children (20 pairs of boys and 20 pairs of girls) participated. In order to examine the associations of temperament and maternal differential behavior with the quality of sibling interactions, mothers were observed in triadic interactions with their two children. On a separate occasion the sibling dyad was observed interacting in the same contexts. The mothers also provided temperament ratings of each of their children's levels of activity, emotional intensity, and persistence. The results indicated that high activity, high emotional intensity, and low persistence levels in both older and younger children were associated with increased agonism between sisters, whereas high activity and low persistence levels for younger brothers were associated with more agonistic behavior among brothers. An imbalance of maternal behavior that favored the younger child was generally associated with lower rates of verbalizations and prosocial and agonistic behavior directed by siblings to one another. The observations of the mother-sibling triadic and sibling dyadic interactions also revealed consistency in the within-family environments. The results are discussed in terms of the importance of considering the within-family environments that mediate the quality of sibling relationships.