摘要：Objectives. We examined the possible public health consequences of adolescent gang membership for adult functioning. Methods. Data were drawn from the Seattle Social Development Project, a longitudinal study focusing on the development of positive and problem outcomes. Using propensity score matching and logistic regression analyses, we assessed the effects of adolescent gang membership on illegal behavior, educational and occupational attainment, and physical and mental health at the ages of 27, 30, and 33 years. Results. In comparison with their nongang peers, who had been matched on 23 confounding risk variables known to be related to selection into gang membership, those who had joined a gang in adolescence had poorer outcomes in multiple areas of adult functioning, including higher rates of self-reported crime, receipt of illegal income, incarceration, drug abuse or dependence, poor general health, and welfare receipt and lower rates of high school graduation. Conclusions. The finding that adolescent gang membership has significant consequences in adulthood beyond criminal behavior indicates the public health importance of the development of effective gang prevention programs. Research has consistently shown that gang membership has proximal adverse consequences during adolescence that, in turn, lead to significant social and economic costs. 1–3 Active gang members are much more likely than their nongang peers to engage in criminal behavior, 2,4,5 especially serious and violent offending 6 ; in addition, they are more likely to be involved in drug use and selling, 5 have more difficulties in school, 4 and are more likely to be violently victimized. 3 However, with few exceptions, there is scant research on possible broader, long-term public health consequences of gang membership. 7–9 Levitt and Vankatesh, 8 in a 10-year follow-up of a sample of Chicago youths, found that those who reported being in a gang during adolescence were more likely to be arrested and incarcerated as adults, were more likely to rely on illegal income, and had obtained less formal education than their nongang peers. When they controlled for background characteristics such as home environment and early school performance, only the relationship between adolescent gang membership and illegal income in adulthood remained significant. In an ethnographic study, Hagedorn 10 conducted follow-up interviews of 228 Milwaukee-based founding male gang members several years after his initial study. Two thirds of the sample did not have a high school diploma or general equivalency diploma (GED), fewer than 32% were employed, and more than 63% had been incarcerated. In a quantitative study involving a community sample, Thornberry et al. 9 examined the extent to which gang membership negatively affected the timeliness of developmental transitions into adulthood, such as completion of schooling and establishment of a career. They found that, after control for individual and environmental risks, male respondents who had been short-term or long-term gang members in adolescence had a greater likelihood of cohabitation before marriage at the age of 22 years than male respondents who had not been gang members. Long-term gang members also had significantly higher rates of unstable employment, school dropout, early pregnancy, and teenage parenthood at the follow-up. Female gang members were more likely to experience untimely or problematic transitions, including unstable employment, teenage pregnancy, and early motherhood. Both male and female former gang members were more likely to report adult arrests. Recently, Krohn et al. 11 found that there was an indirect positive relationship between adolescent gang membership and engagement in street crime and arrest in adulthood. Specifically, gang membership was related to precocious transitions into adulthood that then predicted disrupted family relationships and economic instability. They found that this path eventually led to criminal behaviors at the age of 30 years. In our study, we extended these investigations by assessing the effects of gang membership on adult functioning holistically, examining possible later adult outcomes. Life course theory 12–14 provides a framework to understand how gang membership in adolescence may affect illegal behavior, educational and occupational attainment, and physical and mental health in adulthood. This theory emphasizes the strong connection between childhood events and experiences in adulthood (trajectories), as well as significant events that create a disruption in a trajectory (turning points). Although we did not directly test a trajectory change model in this study, life course theory would suggest that joining a gang during adolescence may initiate a negative developmental cascade into both criminal and noncriminal domains, including decreased educational and occupational attainment and poor physical and mental health. 15,16 Indeed, Melde and Esbensen reported that “youth who join gangs experience noteworthy changes in their emotions, attitudes, and behavior,” 17 (p539) suggesting that gang membership may serve as a significant turning point in an individual’s life course. One such life course theory, the social development model, 18 provides specific mechanisms through which these consequences may operate. This model articulates the mechanisms of socialization and identifies parallel but separate causal paths for prosocial and antisocial processes consisting of opportunities for involvement, actual involvement, skills, rewards, bonding, and adoption of beliefs. Participation in the prosocial path is seen to increase subsequent positive outcomes and decrease risk behaviors. By contrast, participation in the antisocial path is seen to decrease positive outcomes and increase problem behaviors. From the perspective of this model, gang membership in adolescence may serve as a turning point, drastically changing the opportunity structure for young people. As gang-involved youths move through subsequent cycles of socialization, they are likely to experience reduced prosocial functioning across several domains and escalated problem behaviors as they transition into adulthood, even if they are no longer members of a gang. According to Krohn and Thornberry, it is reasonable to expect that being a member of a gang during adolescence will be associated with disrupted transitions from adolescence to adulthood and, ultimately, will adversely impact life chances. 7 (p149) They noted that the challenge is to discover empirically to what extent gang membership contributes to negative outcomes in adulthood over and above general delinquency and other risk factors in adolescence. This was precisely the aim of our study.
