Aggressive and violent behavior is expressed differently across development, but for some adolescents, this behavior leads to criminal justice involvement through arrests and incarceration. Further, according to the biopsychosocial model, aggressive behavior is influenced by both genetics and the environment. This study sought to examine the differential impacts of early childhood environmental cumulative risk and genetic risk on the developmental cascade from middle childhood behavioral aggression and lack of control to adolescent antisocial behavior or callous-unemotional traits, to emerging adult involvement with the criminal justice system, and whether the effects of risk were mitigated by receiving the Family Check-Up (FCU) prevention program in childhood. The sample included high-risk youth (N = 731; 50% female, 50% White, 28% Black, 13% Hispanic, 9% Indigenous, Native Hawaiian, or Asian; of these 13% were multiracial; Mincome = $28,993; representative 515 genotyped) involved in a randomized-controlled trial of the Family Check-Up and followed longitudinally across 11 waves from ages 2 through 19 years. Behavioral measures included parent-report of behavioral aggression and observational lack of control in middle childhood, self-report of antisocial behavior and callous-unemotional (CU) traits in adolescence, and self-report of involvement with the legal system at age 19. Results of longitudinal structural equation modeling (SEM) supported a developmental cascade from middle childhood behavioral aggression to antisocial behavior in adolescence to legal system involvement. Early cumulative environmental risk and polygenic risk tolerance (RT PGS) significantly predicted involvement with the legal system at age 19, while RT PGS also predicted antisocial behavior in adolescence. Further, intervention effects were found for the FCU, such that the FCU disrupted the effects of RT PGS and middle childhood aggression on antisocial behavior and CU traits in adolescence. This study showed that the FCU can mitigate polygenic risk, supporting the benefit of early psychosocial prevention programs. Importantly, this study showed initial evidence that prevention programs targeting early childhood conduct problems could potentially reduce rates of justice system involvement, including arrests and incarceration, by the age of 19.

This study aimed to utilize multiple informant reports to examine whether effortful control (EC) varies across the home and school context among ethnically diverse adolescents attending middle schools in low-income communities and how patterns of variation across context are differentiated by measures of academic functioning and risky behavior. 763 adolescents (50.2% male; Mage = 12 years), their primary caregivers, and two teachers completed measures of adolescents’ EC. Adolescents reported on aspects of academic functioning and risky behavior. Archival data on grade point average (GPA) were collected from schools and adolescents completed the Go/No-Go computer task. Latent profile analysis revealed three reporting patterns: Equal at Home and School (EHS; 43%), Higher at Home and Lower at School (HHLS; 35%), and Lower at Home and Higher at School (LHHS; 22%). Relative to EHS adolescents, HHLS adolescents were less likely to have greater levels of self-reported EC and LHHS adolescents were more likely to have greater self-reported levels of EC. Regarding academic functioning, compared to the EHS adolescents, HHLS adolescents were less likely to have a higher and LHHS adolescents were more likely to have a higher accuracy rate on the Go/No-Go task and have a higher GPA. Compared to HHLS adolescents, LHHS adolescents were more likely to have a higher accuracy rate and a higher GPA. Further, compared to EHS adolescents, HHLS adolescents were more likely to have higher levels of externalizing behavior and the LHHS adolescents were less likely to have higher levels of externalizing behavior. Compared to HHLS adolescents, LHHS adolescents were less likely to have higher levels of externalizing behavior. This study highlights the importance of considering context in the study of EC and the potential use of multiple informants to identify meaningful variation across contexts. In addition, findings from this study can help inform decision-making in prevention and intervention efforts in support of academic outcomes for marginalized youth.

Mediation analysis is integral to psychology, investigating human behavior’s causal mechanisms. The diversity of explanations for human behavior has implications for the estimation and interpretation of statistical mediation models. Individuals can have similar observed outcomes while undergoing different causal processes or different observed outcomes while receiving the same treatment. Researchers can employ diverse strategies when studying individual differences in multiple mediation pathways, including individual fit measures and analysis of residuals. This dissertation investigates the use of individual residuals and fit measures to identify individual differences in multiple mediation pathways. More specifically, this study focuses on mediation model residuals in a heterogeneous population in which some people experience indirect effects through one mediator and others experience indirect effects through a different mediator. A simulation study investigates 162 conditions defined by effect size and sample size for three proposed methods: residual differences, delta z, and generalized Cook’s distance. Results indicate that analogs of Type 1 error rates are generally acceptable for the method of residual differences, but statistical power is limited. Likewise, neither delta z nor gCd could reliably distinguish between contrasts that had true effects and those that did not. The outcomes of this study reveal the potential for statistical measures of individual mediation. However, limitations related to unequal subpopulation variances, multiple dependent variables, the inherent relationship between direct effects and unestimated indirect effects, and minimal contrast effects require more research to develop a simple method that researchers can use on single data sets.

Using data from a randomized, experimental trial of a brief family-based preventive intervention for parentally-bereaved families, this study evaluated whether participation in the Family Bereavement Program (FBP) when the offspring were in childhood/adolescence (ages 8 to 16) improved competencies when the offspring were emerging/young adults (ages 23 to 32). Participants were 244 emerging/young adults; data used were from assessments at pretest, posttest, 6 years post-intervention, and 15 years post-intervention. In addition to testing the direct effects of the program, developmental cascade effects models were used to test the relations between program-induced improvements in positive parenting and decreased negative life events at posttest and subsequent effects on domains of competence and behavior problems in adolescence/emerging adulthood (ages 14 to 22) and four developmental competencies of emerging/young adulthood: academic, peer, romantic, and work competence. Results supported a cascading effects model of program effects on competence outcomes. In the full sample, there were significant mediation effects of the intervention to decreased negative life events at posttest to increased grade-point average (GPA) at the 6-year follow-up to higher academic and work competence at the 15-year follow-up. For females only, two additional significant mediational pathways of the FBP occurred. The FBP led to an increase in peer competence 6 years post-intervention, which was associated with an increase in work competence 15 years post-intervention. Also, the FBP led to a decrease in externalizing problems in adolescence/emerging adulthood, but externalizing problems were positively associated with work competence. For males, additional mediation effects of the FBP on work competence occurred. The FBP decreased negative life events. However, higher negative life events were associated with lower externalizing problems in adolescence/emerging adulthood, and externalizing problems were positively associated with work competence. For males only, a significant three-pathway mediation effect of the intervention occurred on increased positive parenting at posttest to increased romantic attachment at the 6-year follow-up to higher romantic competence at the 15-year follow-up. Peer competence showed continuity over development. Mediational analyses highlighted the role of program-induced improvements in parenting, reductions in exposure to negative life events, and earlier developmental competencies on competence outcomes in emerging/young adulthood. Implications for promoting resilience in parentally-bereaved, at-risk youth are discussed.

This study examined whether the New Beginnings Program (NBP), a preventive parenting intervention, led to changes in coping strategies and coping efficacy in emerging adults whose families had participated in the program 15 years earlier. Gender and baseline risk were examined as moderators of these relations. Participants (M = 25.6 years; 50% female) were from 240 families that had participated in an experimental trial (NBP [mother-only, mother-child] vs. literature control). Data from the pretest and 15-year follow-up were used. Multiple regression analyses revealed that pretest risk interacted with program participation in the mother-only condition of the NBP such that offspring entering the program with higher pretest risk reported significantly less avoidant coping 15 years later. There was a marginal effect of participation in the NBP on problem-focused coping; emerging adults who had participated in the NBP had marginally higher levels of problem-focused coping. There were no significant main effects nor interactive program by risk or program by gender effects on support coping or coping efficacy. Results are discussed in terms of their implications for implementation of preventive interventions and research on pathways of coping.

High-risk sexual behavior (HRSB) and substance use (SU) are highly prevalent in the general population with adolescents and young adults at high risk for engaging in these behaviors. Unhealthy behavioral patterns established during these developmental periods can have detrimental long-term effects on physical and mental health. Health care expenditures, related to consequences of these behaviors, have been estimated to reach around $740 billion in the United States, indicating an imminent public health concern. Unfortunately, little is known about trajectories and risk factors of health risk behaviors (HRBs) beyond age 25, which is a critical developmental period regarding these behaviors. This study sought to better understand HRB trajectories throughout young adulthood as well as the mechanisms underlying the initiation and progression of these behaviors. This study used data from a large (n = 998), longitudinal, randomized-controlled trial with intensive measurement of HRBs and peer and family processes. Growth mixture modeling estimated gender-specific trajectories of HRSB and SU (tobacco, alcohol, marijuana) from ages 22-30. Multinomial logistic regression (MLR) then examined how family and peer factors, and trauma exposure during adolescence, both separately and in combination, influenced HRB trajectories. Four unique trajectories resulted for SU (low use class; increasing use class; decreasing use class; high use class) and three for HRSB (low HRSB class; increasing HRSB class; deceasing HRSB class). There were no differences in the number of classes or trajectory patterns between men and women. Results of the MLRs demonstrated that deviant peer affiliation (DP), family conflict, parental monitoring and trauma exposure impacted trajectories of tobacco and marijuana use and HRSB during young adulthood, but that the most salient influences were DP and trauma exposure. Alcohol use trajectories and differences between the increasing, decreasing and high trajectory classes for the other HRBs were difficult to predict. These results suggest that young adults are still at risk for engaging in HRBs, and there are risk factors in adolescence that influence typologies of HRBs during this developmental period. Prevention and intervention programs targeting young adulthood are needed, and better understanding factors that lead to vulnerabilities specific to this developmental period may inform targeted interventions.

With improvements in technology, intensive longitudinal studies that permit the investigation of daily and weekly cycles in behavior have increased exponentially over the past few decades. Traditionally, when data have been collected on two variables over time, multivariate time series approaches that remove trends, cycles, and serial dependency have been used. These analyses permit the study of the relationship between random shocks (perturbations) in the presumed causal series and changes in the outcome series, but do not permit the study of the relationships between cycles. Liu and West (2016) proposed a multilevel approach that permitted the study of potential between subject relationships between features of the cycles in two series (e.g., amplitude). However, I show that the application of the Liu and West approach is restricted to a small set of features and types of relationships between the series. Several authors (e.g., Boker & Graham, 1998) proposed a connected mass-spring model that appears to permit modeling of more general cyclic relationships. I showed that the undamped connected mass-spring model is also limited and may be unidentified. To test the severity of the restrictions of the motion trajectories producible by the undamped connected mass-spring model I mathematically derived their connection to the force equations of the undamped connected mass-spring system. The mathematical solution describes the domain of the trajectory pairs that are producible by the undamped connected mass-spring model. The set of producible trajectory pairs is highly restricted, and this restriction sets major limitations on the application of the connected mass-spring model to psychological data. I used a simulation to demonstrate that even if a pair of psychological time-varying variables behaved exactly like two masses in an undamped connected mass-spring system, the connected mass-spring model would not yield adequate parameter estimates. My simulation probed the performance of the connected mass-spring model as a function of several aspects of data quality including number of subjects, series length, sampling rate relative to the cycle, and measurement error in the data. The findings can be extended to damped and nonlinear connected mass-spring systems.

To make meaningful comparisons on a construct of interest across groups or over time, measurement invariance needs to exist for at least a subset of the observed variables that define the construct. Often, chi-square difference tests are used to test for measurement invariance. However, these statistics are affected by sample size such that larger sample sizes are associated with a greater prevalence of significant tests. Thus, using other measures of non-invariance to aid in the decision process would be beneficial. For this dissertation project, I proposed four new effect size measures of measurement non-invariance and analyzed a Monte Carlo simulation study to evaluate their properties and behavior in addition to the properties and behavior of an already existing effect size measure of non-invariance. The effect size measures were evaluated based on bias, variability, and consistency. Additionally, the factors that affected the value of the effect size measures were analyzed. All studied effect sizes were consistent, but three were biased under certain conditions. Further work is needed to establish benchmarks for the unbiased effect sizes.

Ethnic enclaves, or neighborhoods with high ethnic densities, have been linked with positive health outcomes and lower crime rates. Using data from the Pathways to Desistance project, this study tested whether neighborhood Latino concentration prospectively predicted re-offense rates among a sample of Mexican American juvenile offenders (n = 247). Further, I tested whether the effect of neighborhood Latino concentration on re-offense was moderated by ethnic identity, Mexican orientation, and generation status. Covariates included demographics and risk factors for offending. Results showed that neighborhood Latino concentration, ethnic identity, Mexican orientation, and generation status were not predictive of re-offense rates. Gender, risk for offending, and time spent supervised during the follow-up period predicted re-offense rates one year later. The results highlight the importance of risk assessment for this high risk group.

Understanding how adherence affects outcomes is crucial when developing and assigning interventions. However, interventions are often evaluated by conducting randomized experiments and estimating intent-to-treat effects, which ignore actual treatment received. Dose-response effects can supplement intent-to-treat effects when participants are offered the full dose but many only receive a partial dose due to nonadherence. Using these data, we can estimate the magnitude of the treatment effect at different levels of adherence, which serve as a proxy for different levels of treatment. In this dissertation, I conducted Monte Carlo simulations to evaluate when linear dose-response effects can be accurately and precisely estimated in randomized experiments comparing a no-treatment control condition to a treatment condition with partial adherence. Specifically, I evaluated the performance of confounder adjustment and instrumental variable methods when their assumptions were met (Study 1) and when their assumptions were violated (Study 2). In Study 1, the confounder adjustment and instrumental variable methods provided unbiased estimates of the dose-response effect across sample sizes (200, 500, 2,000) and adherence distributions (uniform, right skewed, left skewed). The adherence distribution affected power for the instrumental variable method. In Study 2, the confounder adjustment method provided unbiased or minimally biased estimates of the dose-response effect under no or weak (but not moderate or strong) unobserved confounding. The instrumental variable method provided extremely biased estimates of the dose-response effect under violations of the exclusion restriction (no direct effect of treatment assignment on the outcome), though less severe violations of the exclusion restriction should be investigated.