This study examines and discusses sociological and psychological factors affecting adult motivation (or, in general, lack of motivation) to engage in systematic learning or hard intellectual effort. Characteristics and effects of mass culture are briefly noted. Differing levels of learning and conceptualization are described, ranging from the relatively effortless learning of isolated facts (as by mass media) to highly abstract reasoning involving much conscious effort (as in mathematics). Several disciplines are then classified in terms of the kinds of levels of learning required. Play, school life, practical experience, reading, and television are assessed as channels or means of continuous learning. The nature of continuing education and of intellectual effort is also considered. Finally an evaluation is given of age, sex, family status, socioeconomic status, and other background factors as observed in various countries, followed by analysis of curiosity, social advancement, and other motives for educational participation. An annotated bibliography (37 items) is included. (LY)