Introduction to the Special Issue

Mapping the human genome raised high hopes. On the one hand, it promised a better understanding of the origins of both medical and psychological disorders. It also promised to elucidate who would benefit most from a particular treatment. Improving this fit between person and treatment, often known as personalized medicine, should lead to improved efficacy of treatment and reduced side effects. Personalized medicine is now a focus of intense research in fields from cancer treatment to the psychopharmacology of mental disorders. Is this likely to be a productive approach for improving behavioral interventions? Might we expect genetic analyses to illumine parent–child interventions to prevent subsequent child behavioral disorders or to enhance psychotherapy of adolescents or to encourage adults to exercise or to focus policies designed to extend educational opportunities? The current set of nine articles is the first systematic effort, of which we are aware, to survey the possibilities. The Division of Behavioral and Social Research (BSR) of the National Institute on Aging (NIA) planned and initiated this inquiry. Although NIA focuses on midlife and aging, these articles are, by design, relevant to behavioral interventions across the life span. This area of inquiry has been energized by three lines of investigation. First are the well-known studies of gene–environment interaction that have recently been reviewed in this journal and elsewhere. Although the conclusions of some of this work have recently been challenged (Risch et al., 2009), a fair reading of the behavioral and neurobiological approaches to this problem suggests that specific alleles render individuals more sensitive to the adverse influences of stressful social environments (Caspi, Hariri, Holmes, Uher, & Moffitt, 2010) and, quite possibly, to the favorable influences of supportive environments (Kochanska, Philibert, & Barry, 2009). These gene-influenced sensitivities have clear implications for normal and pathological development. Quite naturally, this research on Gene Environment interaction has led to a second line of investigation. Do genotypes of individuals render them more or less responsive to preventive or therapeutic interventions? Several published studies suggest the plausibility of this approach (Bakermans-Kranenburg, Van Ijzendoorn, Pijlman, Mesman, & Juffer, 2008; Bauer et al., 2007; Brody, Beach, Philibert, Chen, & Murry, 2009). A third line of investigation is less heralded. Genetic differences among individuals not only influence their sensitivity to environments over which they have little or no control, but genetic difference also influence how individuals are selected into environments or how they influence and transform their environments (Jaffee & Price, 2007; Reiss & Leve, 2007). For example, heritable characteristics of adolescents can evoke both negative and positive responses from their parents (Narusyte et al., 2008; O’Connor, Hetherington, Reiss, & Plomin, 1995). These data have led to proposals that behavioral interventions could be designed, for example, to alter the response of parents to adverse, genetically influenced evocative behavior of children, a principle already implicit in many parenttraining intervention programs (Kazdin, 1997). Thus, these interventions might be designed to alter the sensitivity of the environment to genetically based selective and evocative influences from children or adults. The articles in this special issue are designed less to report on progress in this field than to stimulate it. They are part of growing effort to forge a community of scholarship linking genetics to behavioral intervention that includes behavioral and molecular genetics, epigenetics and molecular biology, behavioral development, preventive and therapeutic behavioral intervention, and adroit research design and statistical analysis.