A number of factors can influence an individual’s propensity to take risks. In particular, developmental differences in reward sensitivity (attraction to money, food, and other rewards), self-control, and mental representation (the mental picture or interpretation) of choices have each been shown to explain greater susceptibility to risk-taking. Developmental differences refer to how people change with age from infancy to old age. This entry will explain how understanding each of these factors (and developmental trends [Page 1861]in each of them) can help to explain changes in risk-taking that occur across the life span. This entry first defines key terms relating to risk-taking and then goes on to describe developmental trends in risk-taking and how these trends are explained by the leading psychological theories of risk-taking.