Canosa, RobertThe purpose of this study was to examine infant-­sibling behavior in a modified version of the strange situation. Thirty-five mother-older sibling-infant triads were recruited for participation in this study. The sibling pairs were divided into four groups: Male-Male, Male-Female, Female-Female, Female-Male. Mothers filled out a questionnaire developed to assess the degree of sibling involvement in caregiving at home as well as a measure of infant temperament. Predictive relationships were sought between Gender Composition of the dyad, Sibling behavior at home toward the infant, Mother Work Status and Infant Temperament on episode measures of Distress, Play and Contact/Comforting. Results indicated that older siblings can function to reduce infant anxiety in the presence of an unfamiliar person. Low sensitive caregiving by the older sibling predicted higher infant distress and greater contact and comforting by mother during a mother reunion episode. Infants of the gender pair Male-Female exhibited significantly greater distress and required more contact and comforting by mother when she returned than any other pair. Infant shyness was negatively related to sensitive caregiving by the older sibling and to Play in the episodes but positively related to infant distress. The findings are related to the importance of examining the social network within the family when predicting interactive patterns.en-USDissertation