Childhood aggression and adulthood adversities: general and specific associations

Childhood aggression is associated with the development of externalizing problems in adulthood (e.g., criminality, substance misuse). A few studies have found that aggressive children develop also other types of problem, but... [ view full abstract ]

Childhood aggression is associated with the development of externalizing problems in adulthood (e.g., criminality, substance misuse). A few studies have found that aggressive children develop also other types of problem, but it is unknown whether childhood aggression is a non-specific predictor of adult adversities or whether it is specific for externalizing behaviors. 

This prospective twin study is based on a telephone interview with parents to 18,649 9/12 year old twins from the Child & Adolescent Twin Study in Sweden (CATSS). Childhood aggression was assessed with eight items. Outcomes at age 15-21 (severe mental illness, depression, anxiety, anti-depressant/anxiolytic medications, suicide attempts, alcohol/substance use disorders, school failure, social welfare, criminality) were ascertained through national health, demographic and crime registers.

Childhood aggression predicted all the adversities in young adulthood. The outcomes clustered into one general (including all outcomes), one internalizing, and one externalizing factor. Aggression had substantial associations with all factors (general: β=0.43; externalizing: β=0.43; internalizing: β=0.35). Genes contributed to the association between childhood aggression and the general (β=0.35) and internalizing (β=0.33) factors, whereas both genes (β=0.23) and shared environments (β=0.41) contributed to the association with the specific externalizing factor.

Childhood aggression is associated with all types of adversities in adolescence/young adulthood and not just externalizing outcomes. Whereas genetic effects are important for the development into all types of adulthood adversities, shared environmental effects seem to be important specifically for developing externalizing problems. This suggests that interventions for aggressive children should depend on whether the aim is to prevent externalizing or other types of adulthood adversities.