This paper reports on the developmental epidemiological trajectories from first grade through early adolescence of early aggressive, disruptive classroom behavior and the strength of the trajectories in predicting Antisocial Personality Disorder (ASPD) and violent and criminal behavior in young adulthood. We then report the impact of the GBG on each of the three developmental trajectories found to best typify the variation in courses leading to the young adulthood outcomes of ASPD and violent and criminal behavior. By following children from first grade through age 19–21, we investigated the effectiveness of using a universal preventive intervention like the GBG that is directed at early risk factors (e.g. aggressive, disruptive behavior) of later problem outcomes. This paper also is an important extension of the other work in this issue (Kellam et al., in press, this issue
) and on sixth grade conduct disorder (Brown et al., in press, this issue
) in two important ways. First, it investigates developmental trajectories of aggressive, disruptive behavior, not just initial first grade ratings of aggressive, disruptive behavior. Second, the paper analyzes ASPD as well as violent and criminal behavior, two problem outcomes which represent a major public health and public safety concern. Importantly, violent and criminal behaviors were measured by using records of incarceration by young adulthood and therefore are going beyond self reports of the participating youth.
The GGMM analyses revealed three distinct trajectories for males, as hypothesized. There was a group that started high, rose through third and fourth grade, and then decreased somewhat by middle school in aggressive, disruptive behavior over time (i.e., the persistent high
group). There emerged another group with initial moderate levels of aggressive, disruptive behavior that increased over elementary school but not to the higher level of the persistent high
group (i.e., the escalating medium
group). Finally, there was a group that started and remained at a low level of aggressive, disruptive behavior (i.e., the stable low
group). Similar trajectories were found for females in both cohorts, except the medium class did not display an increase in aggressive, disruptive behavior over time; rather it was a persistent medium
group. Across the two cohorts the three trajectories were more similar than different, which lends additional support to the findings. Importantly, these growth trajectories were largely consistent with early starter
and later starter
models of antisocial behavior in keeping with the trajectories identified in the empirical literature (e.g., Broidy et al., 2003
; Cote et al., 2001
; Nagin and Tremblay, 1999
; Petras et al., 2004
; Schaeffer et al., 2003
; Schaeffer et al., 2006
In Cohort 1, the persistent high males and females showed a significant GBG impact on the slope of aggressive, disruptive behavior compared to controls indicating a significantly greater decline in the rate of growth of aggressive, disruptive behavior for the GBG groups. This impact was sustained until the end of elementary school. In Cohort 2, GBG males compared to control males in the persistent high class showed a more favorable development in aggressive, disruptive behavior; however, the impact did not reach the appropriate significance level. No proximal impact was detected for females in Cohort 2.
In both the escalating medium
and stable low
class, no GBG effect was found on the slope of aggressive, disruptive behavior for males in either cohort. The absence of impact in the stable low
class was not surprising because these students continued to behave in a non aggressive, disruptive manner, leaving no room for improvement. With regard to the escalating medium
class, it seems our hypothesis, that the GBG would protect youth from the effects of disruptions in parenting during late childhood and early adolescent years via improvement in social adaptation in the early elementary school years, was not supported. Of note, the growth of aggressive, disruptive behavior showed a precipitous rise after the completion of the GBG at the end of second grade and the beginning of third grade. Thus, it may be that the GBG suppressed the growth of aggressive, disruptive behavior during the period that it was in place, but once the systematic classroom behavior management practices associated with the GBG were no longer in place, the individual, family, classroom, and/or peer group factors hypothesized by Patterson et al. (1992)
to play a role in the late starter
model may have overcome any benefits of the GBG for this group.
These findings provide strong support for the hypothesized link between early and later social adaptation consistent with life course/social field theory, but the question remains about whether the GBG had an impact on APSD and violent and criminal behavior at age 19–21 via the GBG’s impact on the early growth of aggressive, disruptive behavior. As discussed above, in the absence of an established method to test for mediation, we employed a method that approximates the Baron and Kenny (1986)
method. This approximation involved the use of the likelihood ratio test to compare competing models. More specifically, we constrained the path from the GBG intervention condition to the distal outcome within the high aggressive, disruptive behavior class to zero. A significant difference between GBG and control groups was found in Cohort 1 males, particularly for those males who met criteria for both ASPD and violent and criminal behavior. For males in Cohort 2 and females in both cohorts we report null findings.
The worsening in fit when the GBG distal outcome parameter was set to zero was consistent with the expectation that the impact of the GBG on the distal outcome of ASPD was through its impact on the growth of aggressive, disruptive behavior in elementary school. The beneficial mediating impact in the first cohort was replicated for the violent and criminal behavior outcome.
4.1 Reduction of Impact in Cohort 2
The most likely explanation for the lack of significant GBG effects for Cohort 2 relative to Cohort 1 males is the decreased level of mentoring and monitoring in the second cohort (Kellam et al., in press, this issue
). While teachers in the effectiveness trial (i.e., Cohort 1) received 40 hours of training and support throughout the first year, during the following year those same teachers received no additional training and only minimal support for the replication/sustainability trial (i.e., Cohort 2). The reduced level of implementation is consistent with the beneficial but nonsignificant proximal impact seen among the persistent high
males in the second cohort.
In addition, despite great similarities between the cohorts, it was also found that Cohort 2 males started at a lower level of first grade aggressive, disruptive behavior compared to Cohort 1 males (p<0.010). Cohort 2 males were more likely to come from economically disadvantaged families (as indicated by their higher likelihood to receive free lunch); therefore, it is possible that differences in the composition of the risk factors and sample distribution had a negative impact on the power to detect significant associations. Both hypotheses of lower level of implementation and higher individual/contextual risk require further study because the data used in this study are not suited to comprehensively address this issue.
4.2 Reduction of Impact for Females
Because the focus in this study was on overt and physical forms of aggressive, disruptive behavior, the lack of a distal GBG impact for females may be due to the overall lower rates of female aggressive, disruptive behavior and their lower prevalence in antisocial and violent outcomes. Indeed in our sample, the prevalence of females in the persistent high
group was half of that found for males. In addition, in the persistent high
class of Cohort 1, the intercept for females was lower than that of Cohort 1 persistent high
males, indicating the females had an overall lower level of aggressive, disruptive behavior as defined in this study. However, as was shown by Schaeffer et al. (2006)
, the main difference is in the prevalence and not in the growth shape. Furthermore, the proximal impact among the persistent high
females might indicate that highly aggressive, disruptive females respond to the universal intervention in a similar fashion as their male counterparts, lending some modest support to the life course/social field theory being applicable to both genders. It is quite possible, however, that the classroom levels of aggressive, disruptive behavior may impact males and females somewhat differently.
The lack of significant distal impact among females is consistent with findings in cross-sectional and short-term longitudinal studies. This research has found that aggression in girls is associated with peer rejection and depression during childhood (Crick, 1996
; Crick and Grotpeter, 1995
), but a link to serious antisocial behavior problems later in life has yet to be established. In addition, it is possible there are gender differences in the early antecedent risk factors of the developmental courses that lead to later consequences. The course of aggressive, disruptive behavior may manifest itself differently in females, and it may not have the same salience during the course of development nor the same outcomes as found in males. With regards to the last possibility, researchers are starting to explore a broader array of deleterious long-term outcomes that might result from early female aggressive, disruptive behavior patterns, such as health problems (Serbin and Karp, 2004
) and maladaptive parenting (Zocolillo et al., 2004
Our results for females might have been stronger if risks and outcomes more relevant to female development were included. For example, an assessment of relational aggression may have increased our understanding of female antisocial pathways. However, it has been found that relational and physical aggression tends to be highly correlated among both females and males (Henington et al., 1998
; Tomada and Schneider, 1997
), suggesting that females who display high rates of physical aggression may also exhibit high rates of relational aggression. In fact, we found the course of aggressive, disruptive behavior among females differed more in terms of the prevalence than in the developmental pattern. Stronger results might also have been seen if the early antecedent measures included more parameters focused on internalizing behavior, such as depression, compared with more externalizing behavior, such as aggressive, disruptive behavior. Indeed, our previous work has shown that in females later psychological well-being (PWB) is most strongly linked to first grade PWB. Overall it is evident that there is a need for further research about early female aggression and developmental paths that could help more accurately explain the results seen in females with the GBG intervention.
4.3 Strengths and Limitations
A major strength of this study is the design of the randomized intervention trial, which used an epidemiologically defined population of all youth entering first grade in 19 schools. The replication of the intervention with a second cohort adds strength to these analyses as well. Based on the design, we were able to effectively test hypotheses regarding the association between early aggressive, disruptive behavior and later ASPD and/or violent and criminal behavior as well as the impact of a preventive intervention on this association.
The current study focused on the associations of disruptive behaviors observed by teachers in the classroom, thus adding to research on the relationship between school attainment and social adjustment (Dishion, 1990
). Although results from teacher ratings may not be equivalent to those from other sources, such as self, peer, or parent reports, our research as well as the work of other groups has shown that teacher ratings of aggressive, disruptive behavior have the highest level of agreement with student self reports and have equivalent levels of agreement to those found between parent and student self reports of problem behavior (Kellam et al., 1998
; Lochman et al., 1995
; Loeber et al., 1984
Importantly, this research strongly supports predictions based on the organizational approach to development in which we argue that early successful social adaptation in the face of prominent developmental challenges tends to promote later adaptation. In this paper we focused on a critical developmental challenge (i.e., the transition to the first grade classroom) and how this early transition leads to the course of development over elementary school and is related to later developmental outcomes such as ASPD and criminal and violent behavior. We were able to show that under favorable intervention conditions (e.g., sufficient support and mentoring) youth, in particular males, with early social maladaptive responses to school can be helped, and their risk for long-term acting-out negative outcomes subsequently can be reduced.
4.4 Future Research
One direction for future research is to mount a trial where the GBG intervention is implemented throughout elementary school as opposed to only first and second grade. This design might not only improve the impact among the persistent high group, but also more importantly reduce the risk for later aggressive, disruptive behavior and violent and criminal behavior among the escalating medium group. In addition, it might be useful to nest indicated and treatment interventions within a universal implementation of the GBG intervention. In this way, we could address the children who begin to show sub-clinical or clinical levels of oppositional defiant and/or conduct disorder.
We make the argument that the lack of a significant impact in the second cohort was due to lower levels of monitoring and mentoring. However, very little systematic information is available regarding sufficient levels of implementation to detect an intervention impact. Thus, trials that randomize the level of monitoring and mentoring are needed to determine the required amount of implementation to prevent different types of outcomes under different intervention protocols. Importantly, it can be argued that the required level of implementation might be related to the level of risk in the population. The significant intervention impact among the stable low males in the second cohort can be seen as some support for this point of view.
In order to examine the generalizability of the findings presented in this study, replications involving populations varying in terms of ethnicity, socioeconomic status, and neighborhood or community characteristics will need to be conducted. In addition, more research is needed to address the question of how to sustain implementation quality over time and settings, given the decline seen in implementation quality in the second cohort. We have argued that the nonsignificant distal impact of the GBG among females in the persisting high class was likely due to lower prevalence of aggressive, disruptive behavior in females relative to males; therefore, larger samples are needed to provide for an adequately powered statistical test of the GBG impact on females. Finally, testing of the GBG impact on relational aggression may be informative, as would examining the GBG impact on relational young adult outcomes, such as partner violence or parenting.
Understanding variation in developmental processes within and across gender in epidemiologically defined populations is a cardinal requirement for the advancement of prevention programs. A major prevention strategy developed over the last several decades is based on uncovering early antecedents along developmental paths leading to successful and unsuccessful social adaptational trajectories and directing interventions at the antecedent mediators or moderators to promote successful adaptation and well-being as well as prevent problem outcomes (Kellam and Langevin, 2003
). The results reported here support this strategy, but they also point to missing areas of knowledge about development that would allow progress from this strategy to move ahead. Results reported here for males, particularly higher risk males, and the absence of impact for females calls strongly for research in this area of gender and development.