Paul J. C. Adachi

Examining the link between adolescent brain development and risk taking from a social-developmental perspective.

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.

Interpreting effect sizes when controlling for stability effects in longitudinal autoregressive models: Implications for psychological science

Effect sizes in longitudinal studies often are dramatically smaller than effect sizes in cross-sectional studies. Indeed, autoregressive models (which are often used in longitudinal studies but not in cross-sectional studies) control for past levels on the outcome (i.e., stability effects) in order to predict change in levels of the outcome over time and thus may greatly reduce the magnitude of the effect of a predictor on the outcome. Unfortunately, however, there have been no attempts to differentiate guidelines for interpreting effect sizes for longitudinal studies versus cross-sectional studies. Consequently, longitudinal effect sizes that fall below the universal guidelines for “small” may be incorrectly dismissed as trivial, when they might be meaningful. In the current paper, we first review the present guidelines for interpreting effect sizes. Next, we discuss several examples of how controlling for stability effects can dramatically attenuate effect sizes of other predictors, in order to support our argument that the current guidelines may be misleading for interpreting longitudinal effects. Finally, we conclude by making recommendations for researchers regarding the interpretation of effect sizes in longitudinal autoregressive models.

Do video games promote positive youth development

We argue that video game play may meet Larson’s (2000) criteria for fostering initiative in youth, and thus, may be related to positive outcomes such as flow, cooperation, problem solving, and reduced in-group bias. However, developmental and social psychologists examining adolescent video game use have focused heavily on how video games are related to negative outcomes, while neglecting potential positive outcomes. In this article we review the adolescent video game literature, examining both negative and positive outcomes, and suggest important directions for future research.

From outgroups to allied forces: Effect of intergroup cooperation in violent and nonviolent video games on boosting favorable outgroup attitudes.

Here we addressed whether even violent video games can improve intergroup attitudes if played cooperatively with an outgroup, in keeping with the Contact Hypothesis. In addition, we examined potential mechanisms of this effect. In Experiment 1 (N = 77), Canadians played a violent video game (Call of Duty: Black Ops) against zombies, either cooperatively or independently (i.e., at the same time but solo) with a (supposed) University of Buffalo participant. As expected, cooperative (vs. solo) play significantly improved outgroup attitudes and pro-outgroup participant behavior, effects explained by heightened 1-group recategorization (i.e., feeling psychologically on the same team and connected with the outgroup member). In Experiment 2 (N = 239), effects of cooperation (vs. solo play) held whether playing a violent or nonviolent video game. Importantly, our findings offer an engaging and pragmatic solution to the pervasive issue of setting up and negotiating opportunities for successful intergroup cooperation.

The triadic systems model perspective and adolescent risk taking

In this special issue, Ernst (2014) outlines the triadic systems model, which focuses on the balanced interaction among three functional neural systems: the prefrontal cortex (regulation/control), striatum (motivation/approach), and amygdala (emotion/avoidance). Asynchrony in maturation timelines, coupled with less mature connectivity across brain regions, is thought to result in unique vulnerabilities for risk taking during the adolescent age period. Yet, the research evidence linking the triadic systems model to differences in risk taking across adolescence and adulthood is equivocal, and few studies have examined how neural development is associated with real-world behavior. In this commentary, we outline research on adolescent risk taking which highlights the importance of considering trait level and situational conditions when examining associations between neural systems and behavior, as well as the need to adopt a lifespan perspective.