Using the biological and adoptive families in the Minnesota-based Sibling Interaction and Behavior Study, we investigated the associations among genetic and environmental influences on IQ, parenting, parental expectations for offspring educational attainment, engagement in school, and school grades. All variables showed substantial genetic influence, and very modest shared environmental influence. No gender differences were evident. There were significant genetic influences common to IQ and parental expectations of educational attainment, parenting and engagement in school, school grades and engagement in school, parental expectations for offspring educational attainment and school grades, and IQ and school grades. A possible interpretation of the common genetic influences involving parenting is that parents use their own experience with school in shaping the ways in which they parent their offspring.Among developmental and clinical psychologists, parenting is considered to be an important influence on children's academic outcomes (e.g., Gadeyne, Ghesquiere, & Onghena, 2004;Steinberg, Elmen, & Mounts, 1989). This is supported by a large volume of evidence from longitudinal (e.g., Steinberg, Lamborn, Darling, Mounts, & Dornbusch, 1994) and experimental intervention studies (e.g, Forgatch & DeGarmo, 1999), as well as by studies of concurrent associations. Investigations of the mechanisms by which parents exert their effects on academic outcomes tend to follow one of two general traditions (Kellaghan, Sloane, Alvarez, & Bloom, 1993): examination of the effects on children of parental actions, or "what parents do", and exploration of the effects on children of "who parents are". The classic parenting research focusing on socialization activities by parents in the form of emotional tone, disciplinary practices, responsiveness, and expectations (e.g., Baumrind, 1991;Maccoby & Martin, 1983) comes from the "what parents do" tradition, as does research on the quality of the home learning environment provided to children (e.g., Bradley, 1994;de Jong & Leseman, 2001). The "who parents are" tradition is represented by studies positing that socioeconomic and cultural factors carry with them trait-like parental socialization practices with a variety of contextual influences that affect development (e.g., Gallimore & Goldenberg, 2001;Gutman & McLoyd, 2000). Of course, the two research traditions do not necessarily reflect distinctCorresponding author: Wendy Johnson, c/o Department of Psyhology, University of Minnesota -Twin Cities, 75 East River Road, Minneapolis, MN 55455, 952-473-1673, wendy.Johnson@ed.ac.uk. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could...