eroding faith in government, assaults on the natural world (and on animals, with which many young people feel a special affinity), turmoil in racial relations, or growing income inequality. Even with the recent economic boom for some, many teens must worry about having a decent career (not to mention a meaningful one).

These external concerns notwithstanding, teens obviously do not always act in ways that serve their own best interests, even in terms of the goals they set for themselves (which need not correspond to the goals that adults set for them). Worrying about life in general is not incompatible, with teens sometimes underestimating the risks posed by particular behaviors (e.g., unsafe sex, drinking and driving). Nor need teens’ critical decisions be driven entirely by calm deliberation. Of course, adults, too, often have exaggerated feelings of control over life events and, occasionally, let emotion carry them away (Loewenstein, 1996; Weinstein, 1987). However, they may face a lower rate of fateful decisions than do young people, who are trying to set up their lives—including how they will deal with work, drugs, driving, drinking, and intimacy, among other things. Thus, teens themselves create risks that compound those that the world imposes on them.

To deal effectively with these vulnerabilities, teens and adults need to know how big the threats are and how much can be done about them. That means knowing how big the overall burden of adolescent vulnerability is, in order to decide what personal and societal resources to devote to threats to adolescents (relative to other priorities). It means knowing the relative size of specific threats, and of the expected costs and benefits of opportunities for risk reduction, in order to identify the “best buys” in risk reduction. Where these questions cannot be answered confidently, better research is needed, for each link in the analytical chain. Systematic uncertainty reduction is the goal of research focused on patterns of problem behavior and predisposing conditions, creating either vulnerability or resilience (Blum et al., this volume; Jessor et al., 1991).

Where even the best buys are not very attractive, then social investments (including research) are needed to make better options available for youth. The shift from problem-focused interventions to positive youth development ones is a response to feelings of fundamental inadequacy in what we offer young people (Burt et al., this volume). A sweeping change in