Parent-child mutuality in early childhood: Two behavioral genetic studies

Parent-child dyadic mutuality (shared positive affect, responsiveness, and cooperation) is an important component of family socialization processes. T his study sought to extend previous research on mutuality by using a quanti tative genetic design to examine between- and within-family variations (e.g ., sibling differences) and gene-environment processes. The first study inc luded 125 pairs of identical and same-sex fraternal 3-year-old twins. Obser vations of mutuality and parents' and observers' ratings of family environm ent and child behavior were gathered. Greater mutuality was associated with higher socioeconomic status. Moderate sibling similarity in parent-child m utuality was accounted for by child genetic similarity, suggesting evocativ e gene-environment correlation and nonshared environmental processes. These findings were replicated in a 2nd study of 102 pairs of adoptive and biolo gical siblings.