Whether there is a causal link from attitudes to economic success is investigated in this study, which uses data from the Panel Study of Income Dynamics. A theory of motivation is proposed which has two components: motives, generalized dispositions to approach or avoid a class of incentives, and expectancies, an individual's assessments of the chances that his or her own performance will lead to a desired outcome. A positive motive, need for achievement, and a negative motive, fear of failure, are investigated. Generalized expectancies are measured by a personal efficacy index. Future orientation is also measured. An intergenerational analysis of the data focuses on whether motivational deficits among poor parents cause their children to remain at a low level of economic attainment, while an intragenerational analysis examines whether motivational deficits are responsible for poor adults remaining poor. Findings show modest or insignificant effects of motives on economic outcomes and, with one exception, no consistent effects of expectancies on outcome (the exception being an intergenerational one in which parental expectancies are important for young white women). Appended to the narrative are extensive tabular data and descriptions of the study methodology and variables. (CMG)