About 90 percent of parents use some form of corporal punishment on toddlers, and about 50 percent continue to use it during the early teen years, despite a growing body of evidence that it does not positively affect a child's behavior and may actually result in increased aggressive or delinquent behaviors. Straus and colleagues examined the relationship between corporal punishment and antisocial behavior in children.

A sample of 807 mothers with children between the ages of six and nine years was drawn from an original cohort of women who were part of the National Longitudinal Survey of Youth-Child Supplement conducted at Ohio State University. The mothers completed an antisocial behavior (ASB) scale that described their child's behavior over the preceding three months. Descriptive items in the ASB scale included the following: “cheats or tells lies,” “bullies or is cruel or mean to others,” “does not feel sorry after misbehaving,” “breaks things deliberately,” “is disobedient at school” and “has trouble getting along with teachers.” The items were scored as “often true,” “sometimes true” and “not true.”

Categories ranging from no spanking in the past week to spanking 15 or more times in the past week were used to assess the frequency of spanking. For the purpose of statistical analysis, the numbers were broken into four categories of how many times the child was spanked in one week: zero (451 children), one time (160), two times (114) and three or more times (82). Using the ASB scale, data were collected at baseline and again two years later. The study was controlled for several independent variables, including sex, race, socioeconomic status, cognitive stimulation and parental emotional support.

Spanking was significantly related to the ASB score at baseline and two years later. In the zero-frequency spanking group, the ASB score actually declined four points from baseline. In contrast, the ASB score increased 14 points in the group of children whose mothers reported spanking them three or more times at baseline. The consistent finding was that the more frequent the spanking at the beginning of the study, the greater the ASB scores two years later. The trend toward increased ASB scores was stronger in boys than in girls and also in American children of European descent compared with minority children. The tendency also persisted regardless of the extent to which parents provided cognitive stimulation and emotional support to their children.

The authors conclude that corporal punishment or spanking is a statistically significant predictor of subsequent antisocial behavior, even in children who may be spanked only once a week. They believe their data show a “dose response” to corporal punishment, starting with young children. The more frequently spanking is used, the longer its negative effects last and the greater the likelihood that it will induce behavior problems. They further suggest that reducing or completely eliminating corporal punishment would be beneficial to society, since antisocial behavior is associated with violence and more serious crimes committed by teenagers and adults.