Boys who reached puberty earlier than their peers achieved greater success in their careers and experienced more satisfaction in their marriages. The early developers were neither more nor less likely than their peers who reached puberty on-time or late to smoke cigarettes or drink alcohol excessively as adults. In developing an explanatory theory of these findings for further research, the authors suggest that boys who develop earlier than their peers are likely to look older, which may be socially advantageous and contribute to higher levels of self-esteem, as they may be more attractive to girls and draw respect from other boys. Data for this study were obtained from the Terman Life-Cycle Study, which was begun in 1921-22. Pubertal-age data were available for 460 boys. These boys were selected from California public schools for participation in a study of gifted children. There was relative homogeneity in the sample regarding ethnicity (mostly White), social class (mostly middle-class), and intelligence (highly intelligent). Data on psychosocial characteristics were collected at 5-year to 10-year intervals throughout the participants' lives. The variables used in the study were pubertal age, career success (a job that matched their "superior intellectual ability"), marital satisfaction (based on measures of 15 aspects of their marriage), alcohol consumption, smoking, childhood personality, and adult personality. 3 tables and 60 references