["Sociological Forum, Volume 36, Issue 1, Page 111-133, March 2021. ", "\nPrior studies have found college attendance to boost self‐esteem and mastery in young adults. Yet, college attendance itself is likely influenced by self‐esteem and mastery levels experienced in adolescence. And both are likely influenced by adolescent cognitive ability and academic achievement. Using data from the NLSY79‐YA, we illustrate the difficulties in isolating the positive effect of college on young adult self‐concept. First, we estimate adolescent self‐concept trajectories for respondents and analyze whether these trajectories are predictive of college attendance and degree attainment. Second, we assess whether the inclusion of adolescent self‐concept trajectories significantly reduces the beneficial effect of college on young adult self‐esteem and mastery. We also investigate the complex temporal relationship between adolescent characteristics, debt accumulation, and young adult self‐concept. Our findings show that the positive effects of college attainment and debt accumulation on young adult self‐concept are significantly reduced when measures of adolescent self‐concept and cognitive ability are included. These results imply that the benefit of going to college or acquiring debt may be overstated when adolescent characteristics are not taken into consideration.\n"]