This report is a review of current literature on the relation of aptitudes to learning outcomes under different instructional methods or conditions. Included are: (1) aptitude-instructional treatment interaction studies; (2) notes on new methodological problems; (3) and studies of individual differences in laboratory learning arrangements. Aptitudes emphasized include abilities (general, fluid-analytic, crystallized) and personality traits (anxiety, achievement via independence and achievement via conformity). Complex interactions among ability, personality, and instructional treatment variables are demonstrated. Implications for further research are also discussed. (Author)