Researchers have debated whether relational aggression is a developmentally-normative behavior or a sign of some underlying psychopathology. However, due to the dearth of longitudinal studies, we know little about how relational aggression and more severe forms of disruptive behavior co-develop. The present study examined bidirectional associations between relational aggression and two psychiatric disorders, Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD), using data from a longitudinal study of 674 Mexican-origin youth followed from age 10 to 16. Results showed that individuals who engaged in relational aggression tended to increase over time in ODD and CD symptoms, and conversely, individuals exhibiting symptoms of ODD and CD tended to increase in relational aggression. These findings held for boys and girls, for youth born in Mexico and the U.S., and after controlling for physical aggression. Thus, relational aggression seems to be both a developmentally-normative behavior and a predictor of future mental health problems.

Relational aggression-a psychological form of aggression-has numerous negative consequences for physical and emotional health. However, little is known about the risk factors that lead youth to engage in relational aggression. Using multimethod data from a longitudinal research of 674 Mexican-origin youth, this study examined the influence of parents, siblings, and peers on the development of relational aggression. Increases in relational aggression from age 10 to 16 were associated with: (a) low levels of parental monitoring and (b) increased association with deviant peers and siblings. These results held across gender and nativity status. The findings suggest that multiple socialization agents contribute to the development of relational aggression. We discuss the practical implications for reducing relational aggression during adolescence.

Early cognitive development is sensitive to multiple biological, social, familial, and psychological factors. However, discerning the underlying mechanistic pathways has proved to be challenging. Using data from 506 mother-child dyads from the prospective longitudinal birth-cohort of the INMA—INfancia y Medio Ambiente—(Environment and Childhood) Project, this study aimed to test how maternal SES influences early cognitive development, examining potential mediating factors, including maternal mental health, family context, and first nursery school attendance. Results indicate that the association of maternal mental health and SES on early cognitive development is fully mediated by the quality of the family context. Nursery attendance early in life also had a full mediation effect on maternal SES. These findings suggest that epidemiological studies should consider more than SES variables when studying environmental influences on early cognitive development. Policy implications are discussed in the current context of a global likelihood of economic crises and mental health challenges.