Does Spanking Affect the Brain?
A new but limited study links corporal punishment and altered brain response.
Posted May 7, 2021 | Reviewed by Devon Frye
- A recently published study shows that brain activation patterns in spanked children may be similar to those who have experienced outright abuse.
- However, the study's limitations—similar to many corporal punishment studies—may make it easy for opponents to dismiss these results.
- Better-designed studies are needed to more effectively argue against corporal punishment.
The use of spanking and corporal punishment as a form of parental discipline has declined a bit over the years but has overall remained remarkably stable, especially given the fewer and fewer parenting and child mental health experts who advocate for the practice.
The dwindling support for corporal punishment comes from a growing body of research demonstrating that it is not particularly effective and leads to more rather than fewer behavioral and mental health problems down the road. This evidence, however, is imperfect and usually does not involve studies looking directly at the brain.
A recent study, however, did attempt to compare brain activity in youth between those with a history of corporal punishment and those without such history. The sample included 147 youth around 12 years old, 40 of whom self-reported a history of spanking but who had not experienced outright physical or sexual abuse as assessed through various means. This group was compared to 107 youth who had no history of spanking or abuse. There was also a group of 27 children who were spanked but also experienced some kind of abuse. (Author's note: It’s tough to wordsmith these sentences, as I know some people already consider corporal punishment abuse while others don’t.)
All subjects underwent a functional MRI scan which allowed the researchers to look at brain activity in specific regions. In the scanner, the kids were shown facial images, some of which were neutral and others showing responses to threat. The main variable of interest in this study was the difference in activity levels in various brain regions when viewing the neutral versus more fearful faces.
As expected, lots of brain regions “lit up” when looking at more emotionally expressive faces compared to neutral ones. Of specific interest, the magnitude of these differences was greater in the group that had versus had not been spanked. Some of the brain areas in which this was found are the same ones that have lit up when studying individuals with a history of maltreatment and abuse.
These include areas comprising connected regions called the salience and default mode network, which are involved in alerting and orienting to potential threats and in social information processing. The researchers did not find differences in brain activity between the group that had been spanked and the group with a history of physical and sexual abuse.
A couple of caveats are worth mentioning, though. One, some of the brain activity differences between the spanked and never spanked groups were because the spanked group had less activity to neutral faces rather than more brain activity to fearful faces. Also, the authors had expected to see these differences between the spanked and not spanked group in the amygdala, a brain region that is widely known to be important in the detection and processing of fear, but they weren’t there.
The authors concluded that their data support the hypothesis that corporal punishment alters the neural responses to threat. However, they had to admit that “it is not possible to draw causal conclusions” because of the nature of the data.
Lots of studies like this have this fine print qualification about not drawing causal conclusions, but here it is very important for two reasons. First, the media, of course, did anyway, which is typical. Even Harvard ran with the title “How Spanking May Affect Brain Development” while another prominent title was “Effect of Spanking on Kids’ Brain Similar to Abuse.”
Often this can be overlooked because the study authors usually downplay their ability to make causal inferences. Here, however, the design of the study really makes drawing conclusions extremely difficult.
To be clear, I am hardly a fan of corporal punishment, and my latest book which reviews the science on this topic and many others concludes that there is virtually no good data to support its use. The problem, though, is that the ever-increasing mountain of data against it continues to have some of the same methodological problems they’ve had for decades, which makes it all too easy for spanking advocates to simply declare the whole lot of them “flawed” and dismiss them outright. These critiques usually include the following.
- Not testing for the possibility that it is the levels of negative behavior driving the findings (brain changes, physiological differences, etc.) rather than the corporal punishment itself.
- Not being able to separate the effects of corporal punishment from parental behavior that we know is harmful and is often (but certainly not always) associated with corporal punishment, like yelling and harsh criticism.
- Chicken-and-egg problems in determining if corporal punishment is the cause of negative behavior or the consequence of it (or both).
The last bullet is hard to overcome in a study without being able to do something like randomization (which for studies like this is virtually impossible). The first two, however, are more doable and would have been a huge improvement to this study. Had the researchers, for example, compared brain changes that occurred in the spanked group relative to a group of children with similar levels of behavioral problems who had never been spanked (not a super hard thing to do), their argument would have been so much stronger than it is currently.
In the end, we have one more study to add to a pile of literature on corporal punishment that is large, consistent, and flawed. Hopefully, we’ll see some more research that goes the extra mile and provides fewer reasons for the tenacious group of corporal punishment advocates to ignore it.
Cuartas J, Weissman DG, et al. Corporal Punishment and Elevated Neural Response to Threat in Children. Child Development 2021; Apr 9. doi: 10.1111/cdev.13565. Online ahead of print