Spanking Studies Get a Time Out: Take Two

FPG / Retrofile via Getty Images (from Time Healthland)
A new study suggests spanking seriously harms children.  A reader emailed me after reading about it on Yahoo Health.  Here's the claim:  
Spanking children can cause long-term developmental damage and may even lower a child's IQ, according to a new Canadian analysis that seeks to shift the ethical debate over corporal punishment into the medical sphere.  Spanking kids can cause long-term harm, Yahoo Health via Reuters, Toronto, Feb. 7, 2012 
The meta-analysis, published this week in Canadian Medical Association Journal, reviewed spanking studies from the last two decades.  So no fresh data.  I'm no advocate of spanking in fact quite the opposite but this body of research lacks a certain methodological rigor found in other children's health work.  The chief problem - these studies often lack controls for parenting behavior and characteristics so it's dicey to attribute child outcomes (especially IQ) to the spanking and not the parent's other traits or behaviors, other features of the home environment or even the child themselves.  As with any long-term study it's important to gather as much along the path between the spanking and the outcome be it child aggression, depression or academic performance.

One of the better studies actually controlled for quite a few of these parental variables.  The media jumped on it a couple years ago when it was published and generally claimed it as proof spanking caused long-term harm, mainly aggression. In brief it too suffered some flaws.  The main problem? Mothers were the ones who reported on their own kids' behavior and reported the spanking as I noted in a previous post:
This is a self-report study - the mothers reported the frequency of spanking and the child's aggression (e.g., temper tantrums, defiance, physical violence). Would have been much better if we had independent verification of the aggressive behavior from a teacher, day care provider, dad, next door neighbor even. Why?

There may be something about women who resort to physical discipline that also makes them perceive their children as more aggressive.

Maybe limited parenting skills? Being easily frustrated? Lazy? In other words, maybe the kids actual behavior wasn't so bad. Even if the mothers accurately reported the aggression the causation is still uncertain. I can't help but think there's also something about the spankers that makes their kids act up - again, maybe similar suspects like limited parenting repertoire, short-fuses, etc. Momma Data, April 2010
Turns out this study was limited to two years so not exactly long-term.  In addition to this one Carl aka the Numbers Guy at the Wall Street Journal looked at 3 spanking studies in his column a few years ago and basically concluded the methodological limitations precluded any conclusions of long-term harm.

Anyhow, it's worth noting that just as there is no evidence spanking causes serious harm there is no evidence it produces any long-term benefits either.  Possibly short-term benefits according to George Holden, a professor of psychology at Southern Methodist University who's just completed the first "real-time" study of spanking in which his team tracked parents and their kids over 36 hours for 6 weeks on audio. Maybe it will be published and land in the media or a meta-analysis but it's more of a descriptive study of the when/how/why's and won't yield any answers on the long-term consequences of spanking.  It's featured in an article over at Time Healthland if you care to read more. 

Here's the most interesting piece from the media coverage of the recent review of all the spanking data.  According to study author Joan Durant, a professor at University of Manitoba 190 countries have ratified the 1989 United Nations Convention on the Rights of the Child, a treaty for the protection of children from physical and mental violence.  She considers spanking a form of physical abuse and laments that this treaty has been ratified by all UN members except for the United States and sit down -  Somalia and South Sudan.  So I went straight to the United Nations then Wikipedia:

The United States government played an active role in the drafting of the Convention. It commented on nearly all of the articles, and proposed the original text of seven of them. Three of these come directly from the United States Constitution and were proposed by the administration of President Ronald Reagan. On February 16, 1995, Madeleine Albright, at the time the U.S. Ambassador to the United Nations, signed the Convention. It has not so far been ratified; the United States historically has employed a cautious approach to ratification of treaties... President Barack Obama has described the failure to ratify the Convention as 'embarrassing' and has promised to review this. Wikipedia

Wikipedia reports the United States is the only country except Somalia who hasn't signed on and at least the latter has a faminine and a civil war as a convenient excuse.


Awesome Mom said...

It would be interesting if probably impossible to see a study on several different modes of discipline and see what works. Although thinking about it there is no way to actually really do that because each kid is likely to respond better to a different mode of discipline. I know getting grounded never worked for me because I would just read in my room, something I wanted to do any way.

Polly Palumbo, Ph.D. said...

Ahhhh all those studies that would so interesting and so unethical and impossible! If only...
And yes, my daughter doesn't mind at all getting sent to her room. I'd also add that what works at one stage or age is in effective at other ones. I so wish the old "I'm counting to 3" still worked.

JuliesMum said...

And probably impossible too to check that everyone's idea of what constituted spanking was even the same. I can imagine there's quite a spead from the half-hearted and ineffective swipe at the back of the legs, through to consistently inflicting significant amounts of pain. Whether these are interpreted equally by the children will also depend on what they are used to already.

Polly Palumbo, Ph.D. said...

Hi JM! Yes that's one of the frequent issues with self-report. you say swat I say spank. I'd imagine there's considerable variability.