A discussion of the role of affective factors in reading within the framework of the substrata factor theory is presented. The substrata factor theory and theories of the intellect are briefly discussed, and the absence of affective factors in these theories is pointed out. These affective factors are seen as influential in the individual's working system for solving problems, including the problem of learning to read. Learning to read is viewed as a developmental task imposed by society at the time the child enters school, and his previous history in coping with earlier problems and challenges is concluded to influence his approach to this latest task. Research studies discussing such affective factors as self-concept, autonomy, anxiety, an accurate perception of reality, environmental mastery, and attitudes toward learning are reviewed, with emphasis on their influence on learning to read. The need for greater clarification of educational objectives in the affective domain and better methods for evaluating the accomplishment of these objectives are noted. A bibliography is included. (RT)