CHAPEL HILL -- Promises that more than 2.5 million U.S. teens made in the 1990s to refrain from sex until marriage have been surprisingly effective, according to a new study based on the largest survey ever conducted of adolescents in this country. On average, adolescents who took a public pledge to remain abstinent until marriage delayed having sex about one-third -- or 18 months -- longer than others who did not, analysis of their confidential survey answers showed. Such "virginity pledges" work only in specific situations and for specific age groups, however, researchers discovered.
"Our findings surprised us because we didn't expect to see any effect from these pledges, but it was just the opposite," said lead investigator Dr. Peter S. Bearman. "The effectiveness of pledging depends on students' ages. Among adolescents aged 18 and older, pledging makes no difference. Among 16- and 17-year-olds, pledgers delay sex significantly. Among the youngest adolescents, the effect of pledging depends strongly on the social environment of the teen's school."
Bearman conducted the study at the University of North Carolina at Chapel Hill, where he was a former fulltime faculty member, and Columbia University, where he now is professor of sociology and director of the Institute for Social and Economic Research and Policy. His co-author is Dr. Hannah Brückner, a former UNC-CH doctoral student, who now is assistant professor of sociology at Yale University.
A report on the research, chiefly supported by the National Institute of Child Health and Human Development, is scheduled to appear in the January issue of the American Journal of Sociology. Bearman remains an adjunct professor of sociology at UNC-CH. He designed the National Longitudinal Study of Adolescent Health (Add Health) with Dr. J. Richard Udry, professor of sociology and professor of maternal and child health at the UNC-CH School of Public Health. Questions related to virginity were included in interviews conducted in 1994 and 1995 with U.S. adolescents as part of the Add Health study. The Congressionally mandated project involved asking about 90,000 seventh- through 12th-graders at 145 randomly selected U.S. middle and high schools to complete questionnaires about themselves, their health and beliefs. The study's second phase involved detailed, in-home interviews with 20,000 of the teenagers and their parents.
Close to 10 percent of adolescent U.S. boys and 16 percent of girls have taken the pledge since the early to mid-1990s when it became something of a cultural movement, Bearman said. "We found that the effectiveness of pledging among adolescents depended on the characteristics of their school," Bearman said. "In socially 'open' schools -- those in which students had a large number of friends and romantic ties outside the school -- the effectiveness of pledging increased with the number of students who pledged. In fact, a one percent increase in the proportion of students pledging resulted in a two percent increase in delaying sexual intercourse."
In such schools, pledging had no effect if other students did not pledge, he said. Pledging works in "open" schools by making adolescents feel "embedded in a moral community of other pledgers." Researchers observed a very different effect in socially "closed" schools. In those institutions, where most friendships and romantic ties occur within the school, a higher percentage of pledgers actually decreased the promise's effectiveness, Bearman said. If comparatively few adolescents there pledged, the vow was effective in delaying sexual intercourse.
"However, if 30 percent or more of the students pledged, they were no more likely to delay sexual intercourse than were non-pledgers," he said. "Once the pledge becomes widespread, it ceases to have an effect. The effect is meaningful, consequently, only if it is a minority identity, a common situation for identity movements."
Bearman and Brückner also examined the consequences of breaking a pledge. Previous studies found that girls who begin having sex experience a slight decrease in self-esteem. Adolescents who broke their promises, however suffered no greater loss of self-esteem than did non-pledgers. In addition, those who broke the vow were less likely to use contraception during their first intercourse than were those who never promised to remain virgins.
"A typical argument against our findings would be that the kind of kids who pledge are those who would not have sex anyway, and therefore it probably doesn't have any additional effect," Bearman said. "In our study, however, we controlled for the most important characteristics involving the transition to intercourse, and we can say confidently that the delay we saw was real." Compared to non-pledgers, pledgers were more likely to be religious, of Asian ancestry, in a romantic relationship and less advanced in pubertal development. Although those factors are also associated with the timing of first intercourse for adolescents, they do not account for the effect of pledging on delaying first intercourse.
Postponing first sex is important for more than religious and moral reasons, he said. All things being equal, the earlier adolescents have intercourse, the more likely it is that pregnancy, sexually transmitted diseases and disruptive emotional problems could result.
Udry, Bearman and others reported the first findings from the project's second phase in September 1997. Among those were that strong and supportive ties between parents and children help protect adolescents against a variety of risky behaviors, including substance abuse, early sexual activity, pregnancy, emotional distress, suicide and violence.
Besides the National Institute of Child Health and Human Development, the researchers also received support from 18 other federal agencies ranging from the National Cancer Institute and the National Science Foundation to the U.S. Centers for Disease Control and Prevention
Note: Bearman can be reached at 212-854-3094, e-mail: firstname.lastname@example.org. Udry can be reached at 919-966-2829, e-mail: email@example.com. Contact: David Williamson, 919-962-8596, e-mail: firstname.lastname@example.org