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Spanking lowers a child's IQ, researcher says

September 24, 2009 |  6:00 pm

Being spanked as a child is linked to having a lower IQ, according to a study presented today at the International Conference on Violence, Abuse and Trauma in San Diego.

The relationship between spanking and intelligence is found in children around the world, said the lead author of the study, University of New Hampshire professor Murray Straus. Children in the United States who were spanked had lower IQs -- by 2.8 to 5 points -- than those who were not spanked, Straus found.

Straus studied 806 children ages 2 to 4 and 704 ages 5 to 9. Both groups were retested four years later. How often parents spanked influenced IQ score. "The more spanking, the slower the development of the child's mental ability," Straus said in a news release. "But even small amounts of spanking made a difference."

Straus and his colleagues looked at corporal punishment practices in 32 countries by surveying 17,404 university students. The analysis found a lower average IQ in nations in which spanking was more prevalent. The strongest link between corporal punishment and IQ was for those whose parents continued to use corporal punishment even when they were teenagers.

"It is ... time for the United States to begin making the advantages of not spanking a public health and child welfare focus, and eventually enact federal no-spanking legislation," he said.

How would spanking impact intelligence? Straus suggests that the chronic stress created by regular spanking creates post-traumatic stress symptoms in children. PTSD is linked to lower IQ. Economic status also underlies both spanking practices and IQ, Straus said, a leading researcher on corporal punishment. His studies were funded, in part, by the National Institute of Mental Health.
Another study, reported earlier this month in Booster Shots, found that many poor children are spanked at ages as young as 1 and that the practice is tied to more aggressive behavior by age 2 and delayed social-emotional development by age 3.

-- Shari Roan



Photos: The top chart shows the correlation between parents who use corporal punishment with teenagers and the nation's average IQ. The bottom chart shows the more spanking, the greater the likelihood of post-traumatic stress symptoms. Credit: Murray Straus, University of New Hampshire.

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Comments (77)

Federal no-spanking legislation? That is such an absurd idea! Murray Straus must be a control freak.

I'd like to see a study that shows how the IQ of the parents effects the IQ of the child. Probably more significant than the effects of spanking. Like Forest said 'Stupid is as Stupid does...'

My Dad used to whip me with a belt for misbehaving as early as four years old and I was tested at age Five three times with an Avg IQ of 143. Might I have been a Rhodes Scholar had he put me on 'timeout' instead? I guess I'll never know. This was back in the 70's and he came from the days of the great depression when his Dad would make him pick out a switch from the tree with which to get a whippin with when he got out of line. I turned out fine. Gave me discipline and respect for authority at a very early age. People always commented how well behaved I was for my age. Also gave me drive and determination to behave and always do the right thing. I harbor no ill will or have a need for therapy. Matter of fact, just spoke to the old man today and we end every call like we always do. "Love you much." "Ok, love you too." Punishment of a child is a parental right up to a certain point, but legislation for anti-spanking laws is going too far.

i'm fifty years old. i have a 16 year old daughter taking 3 AP courses in High School (straight A's). People also remark on my 4 year old son's communication ability....
I spanked them both....infrequently yes, but it was there. (twice for my daughter, 5 times for my son so far (but not lately).
This "study" is pure crap.
The LAST thing any loving parent needs is to be second guessed by a toddler. I raise my children with love but also with the idea that if a car is coming down the street that they don't see & i tell them to come to me.....
i won't have to say it twice.

ONE study does not public policy make. There is an agenda to destroy Truth. Justice, and the American Way. I imagine the next study from the august professor Straus will indicate, that prison causes crime. If we had no prisons, then we would have no crime. Anarchy.
The Bible says that to spare the rod will spoil the child. And that in the last days, women and children will rule over men. Let's do a study, and see what percentage of prisoners were NOT spanked.
How did we ever make it out of the Cro-magnon caves, build aircraft, go to the moon, split the atom, or create civilization? Obviously, it was all done by people whom were not spanked.
Spanking is the cause of all of societies ills.

Sorry I'm with the "this is carp" crowd.

I was spanked, well deserved, and my IQ is in the 150s....I must have been traumatized or I might have made the 160s!

How our children have been schooled has a lot to do with IQs in the US vs other countries. Different methods and the dumbing down of US students to pass standardized tests the mean nothing does not make for the best environment.

I'm with a few others...I sure hope the tax payers didn't flip the bill for this crap.

I suppose I should point out the obvious that correlation does not equal causation. It's also possible that that stupid people give their parents more reasons to spank them, for example, or that stupid people are more likely to have stupid parents that misuse spanking as a punishment. There is also a difference between being spanked and being "spanked or hit a lot", a difference between being spanked before an after puberty, and a difference between being rarely spanked by a parent that a child knows loves them and being frequently spanked by an abuse parent that obviously hates them. It's also pretty well known that spanking doesn't work on children under 2-3 because they don't understand the punishment (corporal punishment doesn't work on cats for the same reason). If even a small amount of spanking much such a noticeable difference, then why do the claims in this article focus so heavily on the hard cases that are well known to cause problems?

As a child, I was spanked whenever i deserved it, and look how i turned out: valedictorian, and top 4% of the seniors of the state of Nebraska. Not that im bragging or anything, I'm just using it as an example of how spanking did NOT lower my IQ. I think each child has a different discipline method, but i think that spanking is a basic punishment. Because if it's used correctly, and consistantly, it deters the child from repeating the action. But thats the key, consistency. If its not consistant, then you confuse the child, and they dont understand why they are being punished, and so they never learn from it. Instead they may spend their time trying to figure out why they cant do something, sometimes, and other times they can. It's the confusion that prohibits learning, and can even bring down a childs IQ, because again, they never learn.

If the parent were consistant, then the child would soon learn to NOT do something, and they would know that they could'nt do that, and so therefore, they learned something.
That in turn brings up their IQ, because they can reason, that if they can't do one thing, then they probably can't do something that's very similar to the thing they know they can't do, thereby increasing their IQ and reasoning/logical skills.

I believe that living in California reduces a person's IQ.

What a ridiculous, self-serving study used to promote liberal propaganda throughout the USA. What was the study's test group? Twins where one was spanked and the other was not? I don't think so. The National Institute for Mental Health really uses its money wisely.

Lack of discipline and respect for authority in our youth is ruining our society. Why is it that our public schools are a mess and crime rates are increasing. Too much discipline? I doubt it.

Next time you are at a restaurant where a young child is throwing multiple tantrums and the parents are doing nothing, ask yourself, "Would that child be better off with a good, swift spanking? Or does that child seem much wiser than the well-behaved, disciplined child?

Father of six respectful children

Only 23 of the UN's 192 countries legally ban physical violence against children. To grow up and live free from violence is a basic and vital human right. Murray Straus' groundbreaking research makes clear once again in what danger children are who are not loved but abused. They are marked for life by the consequences of these traumatic experiences caused by violence for the human body, soul and mind.
Brain research has proven that putting a child, especially a small child, into states of fear and terror elicits the fight and flight and/or a dissociative response in their bodies, harms the development of their brains, causes brain lesions and changes the brain structure and brain chemistry, which has grave consequences for the adult's health and self-confidence later in life.
The brain is not a fully developed organ at birth. Its growth and development during the first years is dramatic and formative for life. By age 3, already 90% of a child's brain development has taken place as the synapsis between the neurons, the brain cells, are mostly built during these crucial first years. As the human brain is a use-dependent organ, which learns through experiences, violence and fear do terrible damage to a child's developing brain and a human being's potential.
Murray Straus and others, like the neurobiologists Bruce Perry ( and Martin Teicher (;;, share their discoveries and research. We all MUST LEARN from their scientific knowledge, LEARN how to care with respect and love for children so that they never become powerless, defenseless objects of humiliating and perilous violence. Beaten children often will act out (self) destructively, their potential is impeded, and they become unable to make healthy decisions.
Nobody can today ignore these facts and can in good conscience use inhumane violence to "raise" children. Children's chances to become healthy and well-developed human beings are greatly affected and diminished if they must suffer violence by their parents and are thus taught to use violence as a legitimate tool for settling conflicts.
Every time an adult strikes a child, trust is betrayed, the child's well-being is not cared for, his or her health and safety are not protected and the child's life is endangered.
Barbara Rogers
therapist and author of "Screams from Childhood"

This should be an article about how to not over-interpret data.

What is the correlation in the first plot if you remove the outliers: TWN, ZAF & TZA? What is the difference between the title "spanking lowers IQ" and the actual finding of the article "spanking is linked to having a lower IQ"? Does the second graph correlate "spanking" or "perceived amount of spanking" with PTS?

Not as catchy a topic but better journalism.

Doesn't anybody know that IQ is highly inaccurate?! How can you put a number to someone's mind and call it worth? Not only is the thesis of this article faulty, but the method in which he quantified is argument as well. Children are taught the customs of society through being spanked. Mind you I'm not suggesting that beating children is ethical or beneficial, but instead that it's a tool to show what behaviors are accepted in society and which will get you into trouble. Thankfully as a 5 year old you won't go bankrupt or end up in jail for your mistakes, you'll just have a sore bottom for a few minutes. Teacher's, I will say, have no right to touch other people's children and those restrictions should stay in place.

This is such a poorly done study, we might as well admit at this point that the social sciences are all about politics.

The only way you could do this type of a study is with twins since some children are born more aggressive than others and will be punished more often.

I'm sure if you did a cross correlation with parent IQ any correlation with spanking would be negligible at best. But then the media doesn't like to report on parent/child IQ correlations because they represent a challenge to the egalitarian belief of tabula rasa or "blank slate".

You can't assume that spanking is the only thing that affected the kids in the study. I believe in spanking, NOT beating, there is a difference between the two and I think people today associate spanking as a beating. I was spanked growing up and I'm thankful that my parents raised me like that, and I plan on raising my kids that way. I think that people can put money and time to better use than a study about spanking when you can never 100% prove that a lower IQ is from spanking because there are multiple other things that affect a child as well. Children now-a-days are just spoiled and think that they can rule the lives of their parents and it shouldn't be that way. Parents are to be in charge, not children. God says "spare the rod and spoil the child" he's not talking about beating a child, but administering discipline when the child is disobedient. I'm shocked to see the way that 90% of kids act these days and it's so sad to me that it's a surprise when you see kids who are polite and respectful to their parents and that it's rare instead of normal. I am proud to say that my kids are going to be spanked and they will grow up to respect those around them.

As a Parenting Educator for more than 35 years, observing the expectant parents' responses in prenatal classes I taught, I have to say that the spanking issue also illustrates parental IQ.
While I certainly didn't measure their IQs it was obvious that the less educated parent is more likely to rely on personal experience; and they function based on their role models rather than base their beliefs on researched activities.
It usually was the men who had the strongest adverse reaction to my opinion that spanking does no good, and can do a lot of harm. In one class, 2 couples left it immediately, due to one expectant father's objection to hearing about other options to spanking. He shouted as he tugged on his wife's clothing to get her to leave, that he had ".....a right to hit (his) kid if (he) wanted to".
That motivated the others to accept alternatives to spanking. More intelligence is required of parents who think clearly in situations wherein they formerly might have
struck their child(ren). It is also necessary to deduce the "punishment (that) fits the crime".
I learned from the above experience to have class discussion of spanking, its causes and effects, without first giving my viewpoint of it.

Absolutely agree with High Standards MD and Altair Maine. The title is innappropriate and misleading. Which is the chicken or the egg here? The correlation is in no way suggesting that spanking CAUSES the lower IQ. It is in fact equally possible (and likely more probable) that parents with lower IQ's are more likely have children with lower IQ's, and these parents are more likely to spank.

Straus and his colleagues NEED BIG TIME SPANKING to jog their brains, so next time they would not publish anything like this just to gain publicity and fame. This team has very low IQ = they had too much spanking, wow!!!

I hate when people use: "spare the rod, spoil the child" verse as an excuse to hit your children. What I interpret from that verse, is the shepherd and his sheep, when a lamb or sheep stray for the path the shepherd would not beat the sheep, but simply guide the sheep back to the correct path. So the rod is guidance because if we neglect to guide our children back to the path, of course our children will run wild. When does our heavenly father spank us? I believe he guides us, but we make the ultimate choice whether to follow or not. Forget about this article; look at the stats of child related murders due to child abuse and the millions of cases of child abuse in the US alone. Our parents did what did because they were not educated on the subject, but it does not make it right.

I understand what you are trying to say about L.A., but they are just reporting on a study that was conducted by researchers elsewhere. I actually found the research online, then followed a link to the report of it on this website. All I'm saying is that just because the L.A. Times are reporting the study, does not mean that they conducted it. Besides, theories are hardly ever proven by one study.


Violent people are the consequences of violent parents. Any form of hitting must be stopped. Reasonably intelligent people know if you are educating your child about personal interactions you teach them not to hit. I once saw a mother hit her child for hitting another child saying "You don't hit people" as she struck her son. The message loud and clear is you are not people. This totally lends credibility to the fact that hitting lowers IQ, because it's cyclic, the parent has low IQ because they were hit and it becomes a vicious cycle. We learn in school to keep our hands to ourselves, and to not solve problems with our fists...we need that lesson transferred to our homes.


I have to strongly disagree with these findings. My sisters and I come from an abusive childhood and a very controlling environment. However my mentality along with my sisters mentality support the ideas that each individual has their own ability to become what they want to be. Our IQ's reflect on our own abilities to overcome adversity from childhood and develop our lifestyles based off of our own cognitive ideas. It is all but obvious to me that a certain extent of discipline in the rearing of a child, not only constructs a thought process of rigid structure, but also an undefining ability to live a respectful and constructive lifestyle. My older sister became a school teacher, my younger sister is a child abuse investigator and I am studying Architectural / Environmental design. Therefore it is my opinion that the idea of lenient corpral punishment CAN give a child the structure and development techniques we all need to become productive and educated citizens of any culture. The adversity that constricts our own ability to rear a child in a disciplined environment reflects our abilities as adults on how we as adults decide to use the discipline. Not to say that there is a limit to the extent a child should be punished. More so, simple swats on the rear can divert a child from a misbehaving attitude, to a more constructive way of making decisions in his or her own lives.

So we have THREE possible explanations for what is quite striking data:

(1) Smacked children have lower IQs in virtue, not of being smacked, but in virtue of low child IQs being (according to some people here) causally correlated with low parent IQs, and parents with low IQs being more likely (for whatever reason) to smack.

(2) Children with lower IQs are more likely to get smacked (a correlation between low IQ and bad behaviour?).

(3) Smacked children have lower IQs in virtue, not of any causal correlation with their parents IQs, but in virtue of smacking being associated (according to the researchers) with increased post-traumatic stress symptoms, which (according to the researchers) tends to cause low IQs.

So, which of the hypotheses best accounts for the data?

It strikes me as obvious that (3) is correct, given the already well known correlation between smacking->SRESS->low IQ. Please read the whole article before trying to defend your 'right' to abuse children!

Spanking is a lazy parent's way of disciplining their child. Rather than taking the time to find the root of the misbehaviour they lash out and smack their kids. One person commented they were spanked but their parents would calmly explain why they were being spanked. Why not leave it as a calm discussion? I was spanked regularly as a child and never felt I had a voice. I vowed I would never do that to my kids and my strong willed, spirited 4 year old boy is one of the most respectful, thoughtful and obedient children I have met and he has never received a spanking in his life. He is however listened to when upset.
A calm whisper in the ear is just as effective as a smack. Children who have a strong bond with their parents ultimately want to please their parents. Spanking breaks the trust bond.

It never ceases to amaze me that denial will work regardless of the science. People are in denial, either because of what they've done or what they continue to want to do --- beat children.

Did you know that Sweden is celebrating its 30-year national ban on spanking. It's against the law in Sweden, the very first country to ban smacking children. Since 1979, when the Swedes started the children's rights movement, 24 nations have joined them with laws banning corporal punishment of kids. Sadly, the United States is not one of them. Ethic Soup blog has a good post on this at:

More on those 24 countries where spanking is against the law is at:

I do not believe this to be true this was probably research by someone with a perfect little life and have never been spanked. I know plenty of people who have been spanked and my best friend was BEAT! she aced every class in college the whole time she was there up until graduation day. Way to make the research work in your favor ..huh!

Visit to learn more about the sexual dangers of child buttock-battering.



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