A new longitudinal study that looks at how low-income parents discipline their young children has found that spanking 1-year-olds leads to more aggressive behaviors and less sophisticated cognitive development in the next two years. Verbal punishment is not associated with such effects, especially when it is accompanied by emotional support from moms. In addition, 1-year-olds' fussiness predicted spanking and verbal punishment at ages 1, 2, and 3.
The study, which explored whether mothers' behaviors lead to problematic behavior in children, whether children's challenging behaviors elicit harsher discipline, or both, appears in the September/October 2009 issue of the journal Child Development.
It was conducted by researchers at Duke, the University of Missouri-Columbia, the University of South Carolina, Columbia University, Harvard University, and the University of North Carolina at Chapel Hill.
Beliefs onspanking vary across cultures. In this study, the researchers looked at more than 2,500 exclusively low-income White, African American, and Mexican-American mothers and their young children, interviewing and observing them at home when the children were 1, 2, and 3 years old.
All participants' family incomes were at or below the federal poverty level. The authors also uncovered information about the effects of those types of discipline.
"Our findings clearly indicate that spanking affects children's development," according to Lisa J. Berlin, research scientist at the Center for Child and Family Policy at Duke and the study's lead author.
Specifically, children who were spanked more often at 1 behaved more aggressively when they were 2 and had lower scores on tests measuring thinking skills when they were 3. These findings held up even after taking into consideration such family characteristics as mothers' race and ethnicity, age, and education; family income and structure; and the children's gender. The study also found that children who were more aggressive at age 2 and had lower cognitive development scores at ages 1 and 2 were not spanked more at ages 2 and 3.
"So the mothers' behaviors look more influential than the children's," said Berlin.
Unlike spanking, however, verbal punishment alone didn't affect either aggression or their cognitive development. But interestingly, when verbal punishment was accompanied by emotional support from moms, the children did better on the tests of cognitive ability.
The study was funded by the National Institute of Mental Health.