Family instability refers to changes in parents’ residential and romantic partnerships, such as marriage, divorce, and romantic partners moving in or out of the home. As rates of cohabitation, nonmarital births, and divorce have increased over the past 60 years, more children have experienced some degree of family instability. This increase in family instability can have a negative influence on children’s and adolescents’ functioning and behavior.

Not all families have been equally affected by the increase in family instability. Families in which the parents are not married and have low household income are much more likely to experience family instability than families with married parents and higher household income. Family instability influences children and adolescents’ functioning, as
do household income and parents’ relationship status. Family stability can promote positive social behavior in children and adolescents, while instability is associated with social maladjustment, including behaviors such as aggression toward peers, teachers, or parents. This brief examines the links between family instability during childhood, relationship status at birth, and household income in adolescence, and social competence and aggression in adolescence.

Key Findings

  • Family instability was associated with more aggression but was not associated with social competence.
  • Relationship status at birth was associated with social competence and aggression. Adolescents whose mothers were married at birth had higher social competence and lower aggression than those whose mothers were cohabiting or not living with a partner. Adolescents whose mothers were cohabiting at birth had lower aggression than those whose mothers were not living with a partner.
  • Income was significantly associated with social development. Adolescents with household income greater than or equal to 200 percent of the federal poverty line (FPL) had higher social competence and lower aggression than those with household income below 200 percent FPL.
  • Adolescents whose parents divorced had higher aggression than those whose parents stayed married, whereas adolescents whose mothers did not live with a partner at birth—but later moved in with a partner— had higher social competence compared to those whose mothers did not move in with a partner. The breakup of a cohabiting relationship was not associated with adolescents’ aggression or social competence.
  • Divorce was associated with adolescent aggression for those with higher family income.
  • Among adolescents from low-income families, those whose mothers did not live with a partner at birth and later moved in with a partner had higher social competence than those whose mother never moved in with a partner.