心 理 学 报 2008，40（10）：1106~1115 Acta Psychologica Sinica DOI: 10.3724/SP.J.1041.2008.01106 1106 The Early Growth and Development Study: Using the Prospective Adoption Design to Examine Genotype–Environment Interplay Leslie D. Leve Jenae M. Neiderhiser (Oregon Social Learning Center, Eugene, Oregon, USA) (The Pennsylvania State University, University Park, PA USA) Laura V. Scaramella David Reiss (University of New Orleans, New Orleans, LA, USA) (1Yale Child Study Center, New Haven CT, USA) Abstract: The Early Growth and Development Study (EGDS) is a prospective adoption design consisting of 360 linked sets of birth parents, adoptive parents, and adopted children followed from 3 months postpartum through child age 7 years and an additional 200 linked sets for whom recruitment is underway. The EGDS brings together the study of genotype–environment correlation and Genotype × Environment (G×E) interaction to inform intervention development by examining mechanisms whereby family processes mediate or moderate the expression of genetic influences. Participants in the EGDS are recruited through domestic adoption agencies located throughout the United States of America. The assessments occur at 6-month intervals until child age 4-½ years and at ages 6 and 7, when the children are in their 1st and 2nd years of formal schooling (kindergarten and first grade). The data collection includes measures of child characteristics, birth and adoptive parent characteristics, adoptive parenting, prenatal exposure to drugs and maternal stress, birth parent and adopted child salivary cortisol reactivity, and DNA from all participants. The preliminary analyses suggest evidence for GxE interaction beginning in infancy. An intervention perspective on future developments in the field of behavioral genetics is described. Keywords: genetics; adoption; GxE; prevention; childhood There is accumulating evidence indicating that children’s heritable characteristics influence their parents’ behavior towards them (Dunn, Plomin, & Daniels, 1986; Reiss, Neiderhiser, Netherington, & Plomin, 2000), a process known as evocative genotype–environment correlation (rGE). For example, heritable hostile behavior in adolescent adoptees evokes harsh discipline from adoptive parents (Ge et al., 1996), and children with antisocial birth parents elicit more negative controlling discipline from their adoptive parents than do children Received 2008-08-08 The Early Growth and Development Study is supported by the following grants: HD042608, NICHD, NIDA, and the Office of the Director, U.S. PHS (PI Years 1–5: David Reiss, MD; PI Years 6–10: Leslie Leve, PhD); and DA020585, NIDA, NIMH, and the Office of the Director, U.S. PHS (PI: Jenae Neiderhiser, PhD). The full investigative team (Rand Conger, Xiaojia Ge, Leslie Leve, Jenae Neiderhiser, John Reid, David Reiss, Laura Scaramella, and Daniel Shaw) participated in the conduct of this study, and their contributions to this work are deeply appreciated. We thank the participating adoption agency directors and staff members, who made this work possible. Other key contributors to the project include the Advisory Board, study recruiters, site supervisors, biostatistics team, and dozens of other team members who contributed to recruitment, data collection, and data management efforts. Additional thanks go to Matthew Rabel for editorial assistance. Correspondence regarding this article should be addressed to Leslie D. Leve, Oregon Social Learning Center, 10 Shelton McMurphey Boulevard, Eugene, OR 97401-4928, USA. E-mail: [email protected] with nonantisocial birth parents (O’Connor, Deater-Deckard, Fulker, Rutter, & Plomin, 1998). In addition, parenting processes and family context are known to be central in the moderation of genetic influences on child behavior. Genotype × Environment (G×E) interaction effects have been found for a host of outcomes, including conduct disorder, depression, and substance use (Button, Scourfield, Martin, Purcell, & McGuffin, 2005; Cadoret, 1982; Cadoret & Cain, 1981; Cadoret, Cain, & Crowe, 1983; Cadoret et al., 1996; Cadoret, Yates, Troughton, Woodworth, & Sterwart, 1995). For example, Cadoret’s work suggests that adolescents who have an antisocial birth parent and who are reared in an adoptive family with marital problems or psychopathology are at increased risk for aggressivity compared to adolescents with one or neither of these risks. Although the vast majority of GxE interaction studies have focused on individuals aged 5 years and older, GxE interactions are likely to be present in early childhood, when child behavior is amenable to environmental intervention (Fisher & Kim, 2007; Olds, Robinson, Song, Little, & Hill, 2005; Shaw, Dishion, Supplee, Gardner, & Arnds,10 期 Leslie D. Leve, et al. The Early Growth and Development Study 1107 2006). However, adoption studies prospectively examining social processes during early childhood are quite rare, with the current study and the Colorado Adoption Project (Plomin & DeFries, 1985) being the only such studies of which we are aware. The adoption design is a powerful method for detecting evocative rGE and GxE effects because adoption is a natural experiment in which children are reared in families where they are genetically unrelated to their caretakers (Haugaard & Hazan, 2003); therefore, the effects of children on their parents cannot result from shared genes. In the full adoption design (in which data are collected from linked birth parents, adoptive parents, and the adopted child), genetic influences are inferred from similarities between the birth parents and the child, and environmental influences are inferred from associations between the adoptive parents’ behavior/family environmental factors and the child’s behavior. When fundamental design assumptions are met, such as the lack of selective placement and negligible effects of contact between birth and adoptive parents, associations between adoptive parenting and birth parent characteristics are considered as reflecting the evocative rGE processes. As is described in the Future Directions section of this manuscript, the identification of specific evocative rGE and GxE processes can provide insight into