This commentary focuses on several issues concerning research on risk mechanisms that are raised in this special issue. First, we focus on what marks this special issue as distinctive in the ways in which risk research is conducted. Second, several general issues i n research are highlighted, including sample characteristics, measurement strategies, specificity of risk factors and risk mechanisms, categorical vs. dimensional approaches to samples and measures, and definitions of development and transitions. Third, the challenges for integrating alternative models of risk are discussed, with special references to research on genetic and environmental influences on developmental psychopathology. This set of articles is a recent installment in a series of special issues and volumes on development and adjustment in adolescence. The types of samples, risk factors, and statistical analyses used are remarkably diverse, ranging from biological and genetic risks to macroenvironmental influences such as culture and acculturation. Equally significantly, these articles raise many of the more pressing methodological and conceptual issues that concern developmental research. Accordingly, they represent a notable cross-section in the history of risk research.Rather than offer a detailed discussion of each article or of the relations among them-the amount and diversity of information presented precludes this-we structure our discussion on three points. First, we examine the novel research methods and emphases that distinguish the articles in this special issue. Second, we highlight some cardinal issues in identifying risk mechanisms that are common to all the articles. Third, we discuss some implications of these findings for research on risk mechanisms in development.
Changes in Risk Research ApproachesTwo novel trends are especially striking in this set of articles. The first is that possible ethnic and cultural influences on the impact of selected risk factors are prominent. Although broader social systems influence, directly or indirectly, children's development (Bronfenbrenner, 1986), there are many challenges in studying their role. Thus, there is a basic need to determine how culture, a distal factor, might influence individual development through proximal processes. Two examples in this issue are Molina and Chassin's (1996) report on the differential effect of pubertal maturation on parent-child relations, especially with