Longitudinal Effects of Neglect on Aggression and Delinquency: Testing Competing Hypotheses

Background and Purpose: Child neglect comprises approximately 75% of child protection cases, yet it remains understudied. Neglect has documented effects on brain development and emotional regulation, which can manifest as aggression, delinquency, and externalizing behaviors. Yet, multiple forms of child maltreatment (abuse and neglect) are typically examined simultaneously, although examining neglect separately is necessary due to its prevalence and undetermined effects. There are two competing hypotheses about how neglect imparts harm. The cumulative hypothesis posits that ongoing experiences of neglect may accumulate to have increasingly negative impacts on development. The critical period hypothesis posits that there may be a developmental period during which a child is particularly sensitive to the impact of neglect. We hypothesize that there will be a critical period in early childhood in which experiences of neglect may make adolescent aggression and delinquency more likely.

Methods: We used LONGSCAN data (a collaboration between six study sites using prospective data) to examine the longitudinal effects of neglect on aggression and delinquent behavior. We created dummy variables indicating neglect (failure to provide and lack of supervision), across four-year developmental periods: early infancy and toddlerhood (0-4), early childhood (4-8), middle childhood (8-12), and early adolescence (12-16). We assessed aggression and delinquency at ages 12 and 16 with the Child Behavior Checklist (CBCL), which is a multidimensional tool with excellent psychometric properties used to assess child functioning across multiple domains. To test the competing hypotheses, we followed the analyses set forth by Gita Mishra et al. (2009) as a robust and rigorous test of the ways in which a binary predictor (in this case experiencing neglect) measured across time can affect aggression and delinquency. This model-testing approach compares different combinations of exposure to neglect across four developmental time periods representing our competing hypotheses. Regression model statistics are then utilized to identify the best model.

Results: Our results support the cumulative hypothesis at age 12 for aggression, delinquency, and externalizing behaviors. These results were robust in our models with our control variables. However, at age 16, our results were more nuanced. Our analyses supported the cumulative hypothesis for failure to provide, but the critical period (in early adolescence) for lack of supervision on aggression and delinquency. These results were also robust in models where we also controlled for gender, race, poverty, sexual abuse, and foster care placement.

Conclusions and Implications: This is the first study we are aware of that isolates the effects of neglect and examines its longitudinal effects using this rigorous model-testing method. We tested two established hypotheses and found support for both depending on the type of neglect and age of the youth. These findings highlight the importance of differentiating between types of neglect and suggest that CPS workers should view neglect on par with other forms of abuse and work to reduce the harmful effects on aggression and delinquency across developmental stages.