( CNN ) -- In my first job in high school stocking the shelves with fresh produce at the grocery store , I often saw parents struggling with misbehaving children . Some would scream , while others would spank their kids . It was always awkward to witness , because I felt sympathy for both sides . Were the children choosing to act out because the parents were busy and stressed buying food ? But surely the parents could think of a better way to handle a defiant child ? I 'm now a researcher at the Columbia School of Social Work and a specialist in child welfare , and I have just completed a study of this very issue . Columbia colleagues Eric Nicklas , Jane Waldfogel and Jeanne Brooks-Gunn and I published findings in the journal Pediatrics ( PDF ) this week showing that the children who are spanked by their parents are at greater risk for later problems in both vocabulary and behavior . We found that children who were spanked by their mothers at age 5 , even relatively infrequently , went on to have higher levels of behavior problems at age 9 , even after taking into account other family risk factors that also affect child behavior . Given the chicken vs. egg cyclical nature of this , we also controlled for earlier problems with the children to ensure that it was n't just that kids who acted out were simply being spanked more . And 5-year-olds who were spanked frequently , defined as two or more times a week , by their fathers also went on to have lower vocabulary scores at age 9 , even after controlling for an array of other risk factors and earlier child vocabulary . This is an important finding , because few studies in this area have examined effects on cognitive development . A leading researcher on child spanking , Elizabeth Gershoff from the University of Texas at Austin , correctly suggests that some of these cognitive effects may be indirect rather than a result of spanking only . Parents who spank may not talk to their children as often , or kids with behavioral problems may be more distracted at school . To account for some of these possibilities , we did control for a host of other family factors , such as the mom 's IQ , the child 's earlier verbal intelligence , the child 's behavioral problems as well as a measure of how cognitively stimulating the home environment was . So , it appears that spanking is having an effect on vocabulary above and beyond those other factors . Changing people 's minds about something they care about by presenting data is a tough thing to do , particularly around something so emotionally laden as spanking . Thinking back to my times in that grocery store and what the parents were going through , spanking actually worked for immediate compliance : It gets the child to stop misbehaving . The child stops grabbing food off the shelves ; at home , the child stops touching the outlet or breaking his sister 's toy , providing parents with immediate feedback that what they are doing is working . But that makes it more difficult to see what is happening in the long term . How parents discipline their kids is intimately tied to cultural , religious and family traditions , including the meaning parents attach to their own experiences . Many of us say to ourselves , `` I was spanked as a kid , and it made me a good person . So what 's wrong with spanking my own kids ? '' This is a very sensitive topic . That might explain why , even though the evidence is mounting that spanking leads to the very acting-out behavior most parents want to stop and even hurts a child 's development , many parents in the United States continue to spank . More than half of the parents we questioned reported spanking their kids at age 3 and at age 5 , even though our question just focused on spanking in the past month . Studies that simply look at whether children have been spanked at all find that the vast majority of American children are still spanked today . Parents who are interested in exploring alternatives to spanking that might be a good fit for their family can talk to their pediatrician about effective strategies . They can also check out healthychildren.org from the American Academy of Pediatrics , which has some guides for parents on communication and discipline techniques . Perhaps we researchers need to get better at telling the story . Families sometimes think we are accusing them of abusing their kids and challenging who they are as parents , and in turn they dismiss our findings as coming from out-of-touch academics . Most parents are doing the best they can by their children and must contend with advice from many corners , whether solicited or not . Researchers and health practitioners must not lose sight of the burden and stress faced by so many families today , particularly since the tools we hope to see replace spanking sometimes require more upfront effort and consistency in implementation , which can be difficult to maintain without support . We also need to do a better job of conveying to parents what they could do instead of spanking . Parents have a host of tools they can use -- talking , using time-outs and so on -- and all of us who see young parents and children can help demonstrate how effective these other forms of discipline can be . The opinions expressed in this commentary are solely those of Michael MacKenzie .
Michael MacKenzie : Spanking gets results but can harm development . He says kids who are spanked are at greater risk for behavior , speech problems . MacKenzie : How parents discipline kids is tied to cultural , religious , family traditions . Parents have different ideas about how they want their children disciplined and what kind of punishment works best.