The debate over spanking children (corporal punishment, physical punishment) lingers heavily even in 2016. Whether or not hitting your child and causing physical pain is an appropriate means of parenting still results in a healthy argument between parents and even some professionals.
There is now a significant body of research on the topic, the majority of which showing that spanking is associated with negative outcomes. But there has been enough mixed research outcomes and variations in the definitions of physical punishment to leave a toehold for people who still want to argue that spanking is acceptable.
In April, 2016 a study was published in the Journal of Family Psychology that represented one of the most comprehensive reviews of other studies (known as a meta-analysis) to date. It was a rigorous statistical review. It began with a search for research on spanking that produced 1,574 unique studies. After applying many strict criteria (for example, requiring publication in peer-reviewed journals and applying definitions of spanking vs. abuse) only 75 of the studies were accepted. 39 of those studies were new and/or not yet included in any grouped analysis. Over 111 distinct outcomes were analyzed across the 75 studies. 17 specific outcomes were investigated which included the effects of spanking and whether or not there was, for example, more antisocial behavior/substance abuse/low self-regulation/low self-esteem/impaired cognition/etc, in both childhood and adulthood. In total, 160,927 children were studied. The analysis focused of the effect size, which measures the magnitude of the effect of a specific variable:
Thirteen of 17 mean effect sizes were significantly different from zero and all indicated a link between spanking and increased risk for detrimental child outcomes.
Meaning that, even if one could not be sure of the precise size of the effect, it is quite clear that there was a negative effect of spanking.
The authors of this statistical review had published a prior comprehensive meta-analysis in 2002. They were very comprehensive in reviewing and comparing review studies published since then and specifically addressing prior criticism of spanking studies including their own. Answering criticism, the study found:
The finding that the average effect size for longitudinal studies was the same as that for cross-sectional studies.
This finding impressively states that whether the study watched subjects over a long period of time or queried subjects at a single point in time, the results were the same. In fact:
Across study designs, countries, engagements, spanking has been linked with detrimental outcomes for children, a fact supported by several key methodologically strong studies….
Additionally, the review found 7 studies that compared the size of effect between spanking and physical abuse. Interestingly, they found that there was not a significant difference in the size of the effect of the negative impact. Although the effect size for physical abuse was slightly larger, it was not statistically different enough, indicating that the outcomes of spanking were not statistically discernible from physical abuse. (Physical abuse was variously defined, but clearly represented much harsher, arguably illegal, physical contact.)
Now that we have determined that peer-reviewed science supports the notion that spanking is bad and associated with negative psychosocial outcomes in children and adults, we’ll consider the practical implications on parenting, tomorrow, on The PediaBlog.