“Adults smacked as children have higher risk of mental illness later on,” the Daily Mail boldly reports today.
The news is based on a study that investigated whether there was a link between children who were physically punished (for example, spanked) but not abused, and the development of a mental disorder such as depression or alcohol and drug abuse as an adult. This study was based on the results of a nationally representative US survey of 34,653 adults. It found that harsh physical punishment (which stopped short of child abuse) was associated with mood and anxiety disorders, substance abuse and personality disorders.
Although this is an interesting study, it provides no evidence of a causal link between physical punishment and development of a mental disorder later in life. This study also relies upon self-reported information, with adults asked to recall being punished as a child. Both of these facts limit our ability to conclude that smacking causes mental illness. As such, the headline in the Mail is misleading because it does not take into account the limitations of this study.
The study was carried out by researchers from the University of Manitoba and McMaster University, Canada. It was funded by awards from the Canadian Manitoba Medical Services Foundation, the Winnipeg Foundation and the Manitoba Health Research Council among other institutions. The study was published in the US peer-reviewed journal Pediatrics.
The story was picked up by the Mail, which had a misleading headline and incorrectly reported that the study was of just 653 US adults. It actually included 34,653 adults.
This was a retrospective study based on the results of a survey of 34,653 US adults investigating the possible link between harsh physical punishment and development of mental disorders. Data for the study came from part of a larger nationally representative US survey – the National Epidemiologic Survey on Alcohol and Related Conditions, which collected information on over 20s between 2004 and 2005.
According to the researchers, 32 nations around the world have banned corporal punishment of kids, however the US and Canada are not among them. In the UK, parents are allowed to smack their children without causing “reddening of the skin”.
The researchers say that while other studies have examined the link between physical punishment and a broad range of mental health disorders, none have done so in a nationally representative sample that controlled for several types of child maltreatment.
All 34,653 adults were interviewed face-to-face by a trained interviewer. Most of the questions asked were based on a five-point scale (never, almost never, sometimes, fairly often and very often). Childhood physical punishment included events occurring before the age of 18.
To assess physical punishment, the participants were asked: “As a child how often were you ever pushed, grabbed, shoved, slapped or hit by your parents or any adult living in your house?”. Those who answered “sometimes”, “fairly often” or “very often” were considered to have experienced “harsh physical punishment” and were included in the analysis. Harsh physical punishment included acts of physical force beyond slapping, such as spanking.
The researchers wanted to ensure that physical punishment was investigated in the absence of more severe child maltreatment. To do this they excluded from their analysis participants who reported:
Mental disorders over the course of the participant’s lifetime were assessed using valid methods and classified as ‘axis I’ or ‘axis II’ disorders. Axis I clinical disorders included:
Axis II personality disorders were examined individually and classified in three groups:
The results were analysed using statistical methods, adjusting for sociodemographic variables and family history.
Overall, 1,258 (5.9%) of the participants reported harsh physical punishment, without experiencing more severe child maltreatment. The main findings were:
The researchers conclude that harsh physical punishment (in the absence of child maltreatment) is associated with mood disorders, anxiety disorders, substance abuse or dependence and personality disorders in the general population. They go on to say that their findings “inform the ongoing debate around the use of physical punishment” and that the findings provide evidence that harsh physical punishment is “related to mental disorders”. While the researchers suggest that policymakers might consider making a statement that physical punishment “should not be used in children of any age”, they do not call for a definitive “smacking ban”.
This study provides some evidence of a link between harsh physical punishment and lifetime adult mental disorders. It does not provide any evidence that one causes the other. Importantly, there may be many other medical, personal, social or lifestyle factors that contribute to adults developing a mental disorder. There are other limitations to this study, which the authors freely admit:
As a result, the headline that “adults smacked as children have higher risk of mental illness later on” is misleading because it does not take into account the limitations of this study.