The Science of Spanking

The Science of SpankingThere are pictures of NFL player Adrian Peterson’s preschool sons with facial scars and leg lacerations from his discipline techniques. The latest accusations include a head wound Peterson said occurred while disciplining his 4-year-old for cursing at his sibling. In February 2014, a Kansas lawmaker tried to introduce a bill that would have allowed school teachers to spank up to 10 times. In April 2014, Children’s Mercy Hospital announced that all eight of its locations are “No Hit Zones.” CMH is one of a handful of hospitals across the nation beginning to educate the public about physical punishment (sample of one of their parenting handouts). Then there is Peterson who pushed the topic back in the national spotlight. Check out one ESPN commentator’s emotional statement during a discussion about Peterson’s behavior:

With physical punishment still being a hotly debated topic, many have raised eyebrows, asking, “What’s the big deal?” I’m a normal, down-in-the-trenches mom. If you ask my kids if Mommy’s ever spanked them, they’ll say yes. Unlike parents that regularly use a spoon, switch, belt or hand to “guide,” in those rare moments I’ve resorted to spanking, I felt intense remorse. I felt separation and disconnection from my babies who, when they came out of my body, I wanted to put them back inside to protect them. Being the source of their fear and pain in those moments reminds me of my imperfection. They know that Mom isn’t perfect. They know how to forgive. Our relationship repairs teach my children that, even though we make mistakes, both I and they are lovable and capable of getting back to the “good.”

People react intensely to spanking, saying, “It’s a controversial topic.” But to scientists, it’s not controversial. There’s generally a 15-year lag between research and practicing professionals, and another 15-year lag between clinical practice and the public, putting 30 years – 1 or 2 generations – between research findings and public acceptance. With spanking, we are currently in the second lag time. Across child development professions and legislation, it is well understood that physical punishment limits our ability to develop and learn in a healthy way. Here’s what the U.S. Dept. of Health and Human Services and the American Humane Association say about it. The Global Initiative to End All Corporal Punishment of Children names 38 countries that have banned it.

The U.S. is not on the list.

To spank a child is to humiliate and hurt a child in order to suppress a child’s maladaptive, distressed behavior, rather than teach prosocial, desirable behaviors. If you want to make choices about what venue to use to educate your children, have a white meat-only diet, teach your kids to cook and do laundry, drive a horse-and-buggy instead of a car, worship in a church or a mosque, be my guest. We all have the right to parent with our own preferences, but physical violence is a non-negotiable and does not fall into the category of “I’ll do what I want.” Neuroscientists call the flooding of fear a stress “brain bath.” This CNN article compiles studies showing that spanking changes the developmental trajectories of the brain, correlating decreased amounts of gray matter in the brain with children who are regularly spanked.

It’s the same basic process that happens when a sabertooth tiger chases us in the jungle.

  1. A stronger, faster, larger person comes at a child with force.
  2. The amygdala, an almond-shaped organ and the threat-detector of the brain, fires a message, “I’m not safe!” It activates the Fight/Flight/Freeze System.
  3. Cortisol (the “stress hormone”) is produced in high quantities from the adrenal glands. A colleague of mine calls it “pouring diluted Clorox on the brain.” The only way to significantly eliminate cortisol from the body, other than preventing its production in the first place, is through emotional tears (which parents often suppress with, “quit your crying!”) and sweat from physical exertion (think of the exertion of running away from a bear or lifting a burning car off of a loved one).
  4. The sympathetic nervous system takes over the body. Reproductive and digestive systems become slack (sometimes resulting in a child peeing or pooping their pants), pupils dilate, heart rate increases … you get the idea.
  5. Cortisol triggers neurotransmitter spikes: dopamine, glutamate, adrenaline, noradrenaline. When dopamine levels are too high/low, we see impulsivity, inability to focus, and an absence of learning. High glutamate levels are associated with aggressiveness. Boys are vulnerable, as they tend to externalize their emotions physically and get into even more trouble, increasing the risk of being spanked again. Girls tend to internalize with shame and low self-esteem.
  6. Fear shuts down the hippocampus, responsible for memory processing, so often the child will have no memory of why they were spanked.
  7. Blood flow to the prefrontal cortex decreases, particularly the left hemisphere, the part of the brain responsible for reason, cause-effect associations, chronological organization, verbal skills, speech production, learning and memory. If you ask a child to speak to you while you’re disciplining them harshly, they will often not be able to speak or recall clearly with their verbal skills. If you’ve asked your child to recall why they’re in trouble, ever heard a whiny, drawling, “I don’t knoooooooow …”?

Some might say, “Well, it works. I get compliance from my child.” That depends how you measure success. Because of the physical domino effect of stress to the child above, physical punishment is correlated later in life with increased cancer, diabetes, obesity, suicide, heart disease, smoking, mental illness, relationship problems, substance abuse. (Look here, here, here, here.) It works because your child is afraid, but the long term physical and emotional damage is done and gives your child a reason to want to avoid you. Some might say, “Well, I am against spanking, but in extreme circumstances, like when a child is about to run out into the street, it’s appropriate to startle the child to show the magnitude of the situation.” The brain reacts to the shock with the steps above, and in extreme circumstances, you certainly want them to have optimal brain function to learn danger. All the child will remember is that they got spanked, and you did it.

Physical punishment by a caregiver creates a fusion between love and pain, and we wonder as a society why bullying and un-empathetic kids are an issue, why cutting among teens has become a culture or why we have so much difficulty with dating, marriage, divorce and love. If you spank as a method (as opposed to “spanking out of anger”), perhaps the science of spanking will help you reconsider because premeditated spanking is premeditated neurological abuse – you may not see bruises and lacerations, but a child’s brain, internal systems, and relationships pay a steep long-term price. If you have time to think about it beforehand, then you also have time to read and learn. Before commenting on this post, I challenge you to read the 30 years of research, with an overwhelming 93% agreement among studies that physical punishment leads to negative outcomes.

Spanking is an adult self-regulation and expression problem. If you believe you are calm when you spank, consider this: if you were hooked up to bio-monitors while spanking your child, even if you were calm to begin with, the bio-monitors would show spikes in your own cortisol, sympathetic nervous system reactions, and excitatory neurotransmitters as a result of your engaging in aggression. Spanking is not healthy for your child’s brain, but it’s not healthy for yours, either. For those of you who want to use other methods, but think you might resort to spanking:

  • Check out the Research and Resources available online.
  • Examine your own ability to name negative emotions, thus regulating your temper. When you model self-regulation and appropriate expressions of anger, you model these skills to your children, called vicarious learning.
  • Try self-care through venting sessions with a counselor or massage, which decreases cortisol production and increases empathy.
  • Take a look at how you were parented. Perhaps you are an adult who developed in spite of your parents’ physical punishments or humiliations. Here’s the Adverse Childhood Experience (ACE) Scale used by professionals.

No matter how you were parented as a child or what your personal beliefs on this topic might be, please don’t ignore the science behind what continuing this pattern with your child will mean for years to come.

Vanessa Knight has been a part of the Kansas City community for 11 years (a native Texan), living in the Overland Park area with husband Josh, two children (Sophie is 6, Jude is 5), and three Labradors. A clinical marriage and family counselor serving the area, Vanessa works with those who hurt from life experiences, relationships or trauma, helping both individuals and families to love ( When she's not working, Vanessa's favorite stay-at-home things are Sequence, puzzles, picnics on the Nelson-Atkins Museum lawn, messy art projects, and trampoline jumping!


  1. I saw this posted via the Burlington City Mom’s site, and I really appreciate it. It is nice to have research and evidence to support something that I’ve mostly relied on intuition to support. It always gives me pause to hear the many justifications of violence against children. I am hopeful that this secondary lag, is you call it, won’t last much longer.

  2. I don’t believe in spanking (the premeditated, deliberate, systematic striking of a child for any offense), but there are certainly times in life where a parent may react out of fear for their child’s safety and reflexively give them a single pop on the hand or rump as an attention-getter.

    I know from my own experiences that this is quite effective at “marking” an event in one’s mind, and it just so happens to be similar to the example in the article. I ran out into the road as a small child and my mother snagged me out of harm’s way and reflexively swatted my behind, just once. I remember vividly the terrified look on her face, and the way she sank to her knees and hugged me, sobbing, once we were safely back on the sidewalk. She apologized for striking me and explained what I had done wrong, and I understood fully. The only thing I felt ashamed about was that I had scared my mother so badly by doing something so dangerous in the first place.

    I certainly had no trouble learning, functioning or growing into an empathetic adult, and I highly doubt I will get cancer or diabetes from that kind of physical “correction”.

    If your intent was solely to stop the premeditated habitual spankers, then I applaud, but it’s unfair and probably incorrect to make other parents who are not physically violent in that manner worry that a reflexive swat or two over a childhood will permanently damage their child’s psyche or body.

    • Thanks for sharing your childhood memory – the way you described the event (which was similar to the example I used about running into a street) was vivid, and I felt like I was there with you! Perhaps you should write, if you’re not already a blogger… 🙂

      I believe you’re right about the need for parents to not feel anxiety about their mistakes, whether it’s a single emotion-packed swat or a handful of events when a parent spanks over the course of a child’s early years. Certainly, my intent isn’t to be unfair. However, it is not incorrect. Even the single event of having a caregiver hit a child can be damaging, and I will maintain that point because it is evidence-based. Also from my experience as a therapist, I can tell you that many times adult clients will share these isolated memories of their caregivers in childhood that have had profound effects on them. What I believe is really beautiful about your story: your mother apologized for striking you. She was clear about your own mistake, and she was clear about hers. That’s wonderful parenting, and it’s clear that she wanted to protect you. Her ability as a mother to admit and repair after her impulse to strike out of fear (a fight/flight response misdirected) is also a part of your story, and it’s probably part of the reason why you are such a functional, growing, empathetic adult. I’m grateful that you shared it in such detail. Parents shouldn’t feel continual shame and anxiety about the imperfections they have in parenting. A perfect parent doesn’t exist. There’s another blog post I’ve done from the past called “Mommy Crucifixion” that addresses anxiety about mothering with mistakes, so for now, I’ll sign off 🙂

      Thank you so much for sharing. I loved your story.

  3. I really enjoyed this article. I do not spank my child an I was not spanked as a child. I see absolutely no reason to discipline with violence and it greatly disturbs me when I read religious justifications for spanking. Your POV was well researched and you have handled criticism with grace. Well done.

  4. Mother cats will bat their kittens if they are too rough When playing, mother dogs will punish their puppies if they play too rough or do not listen. If punishment is not required why is it used in nature so much? Children need the negative reinforcement and consequences. Explain before “don’t do that” a slap on the hand and an explanation “that happened because you did that” still gets the message across without a long drawn out spanking session and no explanation of what the hell they did to get spanked. My parents were bad about that. Remember parents, the kid has no idea why you spanked them or what behavior was bad if you don’t say anything. All I have memories of is my mom spanking me and no idea what I did that made her do it. Thus I was spanked more because I didn’t know what behavior was bad.

    Maybe not spanking, but no punishment at all leads to terrible spoiled, egotistical, human beings, and it’s every parents job to make their child a decent human being the rest of us don’t want to kill.
    When kids are given all positive reinforcement they bluntly, become annoying spoiled [expletive] that act how they want because they know they will never be punished.

    • Hello BC –

      Thanks for integrating animals into your comment, and thank you most of all for sharing your childhood experience.

      You are correct that dogs and cats will use physical intervention to teach submission and trust, but rarely (unless there is a behavioral dysfunction in the parent animal, often because of experiences the parent has had with humans) do cats and dogs ever inflict pain. The types of physical interventions they use generally involve strong holding, such as subduing a overly-enthusiastic puppy by placing a leg or paw on the puppy’s neck and holding the puppy down until it calms and relaxes under the proprioceptive pressure.

      I would like to redirect you, however, to a different mammal group for comparison: primates (our closest relatives in the animal kingdom). If you watch video documentaries of gorillas or chimps in the wild, they never strike their young. Only in captivity do primates display signs of violence or physical aggression. In the wild, the only records of violence in gorilla troupes happens when a dominant, fathering male dies: the new male who takes over the troupe will sometimes commit infanticide, killing the young that belonged to the previous male. It’s also noteworthy that, most often, the females will disband in order to protect their infants from this.

      You are correct that “no discipline” results in self-centered adults. I 100% agree. But discipline is not the same as punishment. Discipline does can be gentle redirection, engagement or even play), and many other things – think of discipline in martial arts, music, academics. Discipline simply facilitates learning of new skills. If we are to learn from nature what is appropriate for discipline, we actually see that animals are much more gentle with their young than humans, and you are right that we should take a cue.

  5. I am really disappointed that the City Moms franchise is promoting a post that seems to equate Adrian Peterson’s beatings with spanking. That’s an odd stand to take, and perhaps not one that their advertisers would agree with. Beating and leaving scars and open wounds is not the same thing as a spanking, and I would expect a parenting blog group to know that.

    I’m not sure if this post is meant as click-bait or SEO designed to draw page views, or if it represents the honest opinion of the franchise as a whole. I’m not comfortable with any of the above. I’m cutting bait with City Moms.

    “Unlike parents that regularly use a spoon, switch, belt or hand to “guide,” in those rare moments I’ve resorted to spanking, I felt intense remorse.” This statement bothers me. A great deal. It comes across as condescending and judgmental. “It’s okay when I do it because I do it the right way, unlike those other people.”

    Spanking is a hot-button topic, and it needs to be approached with more care than is given here if a true dialogue is to be opened.

  6. Thank you for the article. As a new parent, I have been thinking a lot about how my husband and I will handle discipline. I was spanked as a child but my husband was not. I really appreciate the information about the science behind spanking. I am also going to check out Daniel Siegel’s new book. I look forward to future articles exploring alternative discipline practices.

  7. Congratulations on having the luxury of writing a blog article, which is a clear artifact of an advanced culture built largely by people who were spanked as children by parents and even schoolteachers. This is also further evidence that scientific study is no longer proffering theory, but is peddled like fact on every media outlet by people who regard it as flawless (despite the fact that humans are performing said research, much of it with questionable controls and agendas). What’s more, there are generations of loving parents who are revered and adored by their children, passing along their admirable character qualities free of guilt. And they certainly don’t need to retroactively feel any guilt based on whatever brand of science is represented here. Life cannot be reduced to the quantifiable, despite the advancement of science AS religion. If you love your children well with a detectable humility and a commitment to discipline, spanking or not, you’ve got a great chance of success.

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