Such research increased enormously during the 1970's, largely under the impetus of Federal funding. The research shows a marked increase in nonmarital intercourse among teenagers during the early 1970's. A cluster of interacting biological, social, and psychological variables have been identified with both early nonmarital coitus and contraceptive behaviors. Such factors include a low level of religious commitment, permissive sexual norms in the larger society, racism and poverty, low educational goals and poor academic achievement, deviant attitudes, early puberty, and being older than 16. The direct social and psychological effects of early childbearing, per se, are apparently minimal for young people in many aspects of their later lives, particularly when appropriate statistical techniques are used to control for the impact of socioeconomic status and race. Studies show an impressive improvement in methodology between 1970 and 1980, but progress in sophisticated conceptualization of the issues remains minimal. 1 table, 53 references.