The current study explored individual differences in ability and motivation factors of retention in first-year college students. We used discrete-time survival mixture analysis to model university retention. Parents' education, gender, American College Test (ACT) scores, conscientiousness, and trait affectivity were explored as predictors of retention. Results indicate gender, ACT scores, and conscientiousness are significant predictors of retention, but parents' education level was not a significant predictor. Positive affectivity and negative affectivity also were significant predictors of university retention when added to the model. Interestingly, once affectivity was added to the model, conscientiousness was no longer a significant predictor, indicating conscientiousness may be an amalgamation of motivation and ability. Implications for research and theory are discussed. (Contains 1 table and 3 figures.)