Teenagers who have recently moved are more likely than others to begin having premarital sex, but moving itself—which has adverse consequences on a range of adolescent behaviors—does not explain the adoption of this behavior.1 In a sample of youth participating in the first two waves of the National Longitudinal Study of Adolescent Health (Add Health), the proportion initiating sexual activity between interviews was significantly higher among those who had moved shortly before the first wave (23%) than among those who had not (18%). However, when a wide range of background and psychosocial characteristics were controlled for, having moved was not significantly associated with initiation of intercourse. Rather, relatively poor academic performance and high levels of delinquency among both youth who had moved and their friends in school were predictive of their increased likelihood of beginning sexual activity.

To examine the factors underlying previously established links between residential mobility and adolescents' initiation of premarital sexual activity, researchers analyzed data from Add Health respondents who reported being sexually inexperienced at Wave 1 (conducted in 1994-1995) and had not married by Wave 2 (1996). In addition to teenagers' background characteristics, residential mobility before Wave 1 and sexual behavior, the analyses included measures of their risk behavior, relationship with their parents and psychological well-being; the structure of their school-based social network; and the behavior of the youth in that network. The analytic sample consisted of 4,862 teenagers, of whom 20% first had intercourse between survey waves.

Sixteen percent of respondents had moved within the two years prior to the first interview, and bivariate analyses revealed many differences between these youth and others. They reported a higher prevalence of sexual initiation between surveys (23% vs. 18%) and differed from youth reporting no move on almost all background characteristics studied. Those who had moved were younger than others at Wave 1 (14.3 vs. 14.6 years, on average), were less likely to be white (67% vs. 78%) and to live in a two-parent family (71% vs. 81%), and were more likely to be receiving public assistance (9% vs. 6%) and to report that their parents had recently divorced or separated (7% vs. 3%). They had a higher risk profile than youth who had not moved (as suggested by a lower mean grade point average and less involvement in extracurricular activities), and they scored lower on all three parent-child relationship measures (which reflected quality of the relationship, parents' involvement in their child's life and parents' availability to their child). Measures related to their network structure indicated that they were more isolated from their peers, were less well connected and had less popular friends than teenagers who did not report a recent move. Finally, the friends of youth who had moved had a lower mean grade point average and participated less in extracurricular activities than the friends of other respondents.

In an initial logistic regression model, controlling only for teenagers' background characteristics, youth reporting a recent move at Wave 1 had a significantly elevated likelihood of beginning to have sex by Wave 2 (odds ratio, 1.4). Additionally, the older a teenager was, the greater the likelihood of sexual onset (1.4); the odds declined if the parents were well educated (0.9) and if the teenager lived with both parents (0.5).

Building on this model, the researchers conducted a series of analyses, first adding the different types of measures individually and finally controlling for all of the variables at once. When the model controlled for either parent-child relationship factors, psychological well-being or network structure in addition to background characteristics, the association between a recent move and sexual initiation was unchanged.

However, when the analysis controlled for individual risk behaviors, the relationship was no longer statistically significant. In this model, the lower a teenager's grade point average, the higher the odds of sexual initiation, and the odds were elevated for respondents reporting delinquent behaviors. Similarly, in the model controlling for the behavior of teenagers' friends, youth who had moved shortly before Wave 1 did not have an elevated likelihood of beginning to have intercourse; sexual initiation was positively associated with peers' delinquency and inversely associated with their grade point average.

When all measured factors were controlled for simultaneously, youth reporting a recent move were not significantly more likely than others to have started having sex between surveys. For most background variables, results were similar to those of the initial model. Moreover, the likelihood of sexual initiation remained inversely associated with teenagers' grade point average (odds ratio, 0.8) and was significantly elevated among those who reported that they or their peers engaged in delinquent behaviors (1.2 and 1.1, respectively).

The researchers conclude that the "behavioral composition" of the social networks of teenagers who have moved, as well as these teenagers' own risk behaviors, best explains why they are more likely than others to begin having intercourse. In the analysts' view, the dynamics within "low-performing and relatively delinquent" networks may make it easier for teenagers who have recently relocated to join them than to join higher status groups; this relatively easy entry may lead youth to adopt the behaviors that are prevalent among members of the network, including sexual activity.—D. Hollander


1. South SJ, Haynie DL and Bose S, Residential mobility and the onset of adolescent sexual activity, Journal of Marriage and Family, 2005, 67(2):499-514.