A large body of research has identified a number of factors that underlie adolescent sexual and contraceptive behavior, pregnancy, and childbearing. Several recent reports summarize these studies.(1) Moore and colleagues consider five types of influences that contribute to these behaviors: biological; family, peer, partner and sibling; community; policy; and media. Among the many factors in each of these categories, they identify four that are most predictive of early pregnancy and childbearing: poverty, early school failure, early behavior problems, and family problems.(2)
Kirby provides a three-part framework for organizing factors underlying teen pregnancy and childbearing. There are biological antecedents, including gender, age, testosterone level, and timing of puberty. Research has shown that these factors are causally related to adolescent sexual and contraceptive behavior and pregnancy, and they have moderate effects. A second group of antecedents can be viewed as manifestations of social disorganization or disadvantage. These include factors in the community and the family: violent crime, poverty, unemployment, family marital disruption, parents' lack of education, mother's and/or sister's being an adolescent mother, poor child rearing practice, lack of parental support and/or supervision, and inappropriate sexual pressure or abuse. The second group also includes factors in the individual teen: lack of religious affiliation, drug and alcohol use, aggressiveness, engaging in other problem behaviors and deviance, delinquency, poor educational performance, low educational expectations, low expectations for the future, and external locus of control. Research has shown that these factors are associated with adolescent sexual behavior and pregnancy-some strongly, some weakly, some in varying degree depending on the study. A third group of antecedents are attitudes and beliefs about sexual behavior, pregnancy and childbearing; these include beliefs, personal values, and perceived norms and intentions. Research has shown that most of these factors are weakly or moderately associated with sexual behavior and pregnancy, with some variation from study to study.
This large, complicated, and interrelated accumulation of factors suggests that the course that leads to adolescent sexual activity, contraceptive use, pregnancy, and childbearing is complex. Kirby concludes that "not merely one or two, but a multitude of antecedents are related to one or more sexual or contraceptive behaviors, pregnancy and childbearing, including characteristics of the teens themselves, their peers and sexual partners, their families and their communities and states. No single one of these antecedents is highly related to behavior; rather, each of many antecedents is weakly (or, in some instances, moderately) related to behavior."(3)