To Spank or Not to Spank?

abstract & Commentary

Source: MacMillan HL, et al. Slapping and spanking in childhood and its association with lifetime prevalence of psychiatric disorders in a general population sample. CMAJ 1999;161:805-809.

Whether to spank or not to spank children as a form of punishment in the home (and, in some parts of the country, in the school) is one of those controversial child-rearing issues about which every clinician has a strong opinion. Often this opinion is based on personal experiences—how one was raised and how one is raising (or has raised) children—as opposed to the results of scientific studies. MacMillan and colleagues used a population-based study in Ontario, Canada, to examine how often adults report that they were spanked or slapped during childhood and to determine possible relationships of this to psychiatric disorders. Similar findings have been reported from the United States.

Data for this study came from the 1990-1991 Ontario Health Supplement, a survey of 9953 residents who were at least 15 years of age. All were asked about slapping or spanking: "When you were growing up, how often did any adult slap or spank you? Often? Sometimes? Rarely? Never?" To examine the association of spanking per se with psychiatric disorders, the following respondents were excluded: Those older than 64 years of age, those who reported a history of physical abuse and/or sexual abuse, and those with missing information. A total of 4888 people were included in this part of the study. Psychiatric disorders were ascertained by a structured interview.

The majority of respondents (80%) reported that they had been slapped and/or spanked during childhood; often, 5.5%; sometimes, 33.4%; or rarely, 40.9%. The remaining respondents (20.2%) reported never being slapped or spanked. Females reported never being slapped or spanked more frequently than males (23.9% vs 16.4%). Because of the wording of the question, it is unclear whether the spanking or slapping was by a parent or another adult.

There was a statistically significant association between the reported frequency of being slapped or spanked and anxiety, alcohol abuse or dependence, and externalizing problems such as antisocial behaviors or illicit drug abuse or dependence. An association also was noted for major depression, but the p value was 0.08.

Comment by John M. Leventhal, MD

Here is yet another study demonstrating that physical punishment is prevalent in North America and is associated with long-term adverse outcomes in three of the four psychiatric disorders examined. A major strength of this study is the exclusion of adults who reported sexual abuse and/or physical abuse (24% of the sample) because these childhood experiences, by themselves, have been associated with psychiatric disorders. A major limitation of this study is a failure to control for other important variables in the family, such as an alcoholic parent, domestic violence, parental divorce, etc.

It is clear from this study and others that investigations on the long-term (or even short-term) consequences of spanking are methodologically difficult to conduct. Of course, the perfect study—a randomized, controlled trial of spanking—is not ethically possible, so we are left with observational studies and potential biases. In such studies, the most important bias is the failure to control for critical family variables that are likely to be associated with the occurrence of the outcome.

A second important potential bias relates to people’s memories about how they were raised. For instance, in MacMillan et al’s study, if respondents with alcohol-related problems over-reported the frequency of slapping or spanking, then these falsely inflated frequencies would result in a false association with the outcome of alcohol abuse or dependence.

For those who believe that spanking is not good for children, the results of this study will provide further support; for those who favor physical punishment, the limitations of the study will be noted. It is hard to imagine a study design that would convince those at the extremes. Keep in mind, however, when studies examining the short- or long-term consequences of physical punishment do find an effect, it is usually a negative effect. (Dr. Leventhal is Professor of Pediatrics at the Yale School of Medicine, New Haven, CT.)