Marriage does not improve children’s outcomes

19 April 2010

Parental marital status is not the primary cause of differences in children’s social, emotional and cognitive development between those born to married and cohabiting couples, according to new research from the Institute of Fiscal Studies (IFS).

The IFS, funded by the Foundation, examined data on 10,000 three and five year olds and concluded that developmental differences between children born to married parents and those born to unmarried parents are not primarily accounted for by marital status, but determined by other factors, such as parental age, education, and income.

The researchers, led by the IFS Deputy Director Alissa Goodman, identified several reasons why children born to married parents have higher developmental outcomes than those born to unmarried parents; their parents are older, more educated, have a higher household income, and a higher occupational status, as well as a higher relationship quality early in the child’s life.

Factors such as education, income and occupation are significant in whether people choose to marry or to cohabit, which is why it can appear that children born to married parents achieve better outcomes, but the evidence shows that once these differences in parental characteristics are accounted for, parents’ marital status appears to have little or no impact on children’s cognitive development. Even in the case of children’s social and behavioural outcomes, where relationship quality is important, the question is whether marriage causes or results from better quality relationships.

The research has implications for policy makers interested in improving child outcomes because it suggests that a simple increase in the number of couples getting married would have a limited effect on children’s development up to the age of five.

Further findings

  • There has been a very large increase in the number of births outside of formal marriage in the last 25 years. In 2008, 3 out of 10 births in England and Wales were to cohabiting parents.
  • By the time children are aged 3, children born to married parents display better social and emotional development and stronger cognitive development than children born to cohabiting parents, and this can also be seen at age 5. At both ages, the differences in children’s social and emotional development are much larger than the differences in their cognitive development.
  • The gap in cognitive development at ages 3 and 5 between children born to cohabiting parents and those born to married parents is not statistically significant, once differences in parents’ age, education, occupation, income and housing tenure are taken into account. In other words, marriage does not change the educational, financial or housing situation of parents, but people with more educational qualifications and higher incomes are more likely to get married.
  • The gap in social and emotional development at ages 3 and 5 between children born to cohabiting parents and those born to married parents is reduced by more than half, but remains statistically significant when differences in parental education and socio-economic status are accounted for. Once the likelihood of a pregnancy being unplanned and the relationship quality when the child is 9 months old are also accounted for, the gap in social and emotional development between the children of married and cohabiting parents becomes statistically insignificant. Marriage may well improve relationship quality, but couples are also more likely to marry when they feel their relationship is good.
  • The findings cannot provide a definitive estimate of the causal impact (or lack of impact) of marriage, but unlike previous work in this area, the report accounts for differences in the prior characteristics of parents that reflect differences in the circumstances of couples who decide to enter into marriage. By doing this, the report aims to provide a more accurate estimate of the true impact of marriage on children’s development.
  • A second part of the study will look more closely at the issues of relationship quality and outcomes for children, and will appear later in the year.

The report, Cohabitation, marriage and child outcomes, is available to download from the IFS website.