Sticks and stones indeed break bones -- but words can cause real harm to kids, too, a new study says. And bullies in the school yard aren’t the only ones to blame.

"Harsh verbal discipline" on the part of a parent increases a child’s risk for depression and aggressive behavior, and is "not uncommon," according to the research, which was published online earlier this week in Child Development. The disciplinary techniques in question include yelling, cursing and humiliation -- defined as "calling the child dumb, lazy, or something similar."

The study even suggests that verbal reprimands can have the same impact on children as physical punishment: "the negative effects of verbal discipline within the two-year period of [the] study were comparable to the effects shown over the same period of time in other studies that focused on physical discipline," a press release from the University of Pittsburgh, where the study's lead author is an assistant professor, explains.

The study followed 976 Pennsylvania 13- and 14-year-olds and their parents for the 7th and 8th grade years, and found that the depression or poor behavior increased in the children who were exposed to harsh verbal discipline. Instead of serving to remedy the issue, verbal discipline tactics seemed to provoke the unwanted behavior.

"Adolescence is a very sensitive period when [kids] are trying to develop their self-identities," study leader Ming-Te Wang told the Wall Street Journal. "When you yell, it hurts their self image. It makes them feel they are not capable, that they are worthless and are useless."

Wang added to NPR that the study was "a reminder to [parents] that we need to stay calm," going on to recommend "two-way interventions for parents and kids."

Neil Bernstein, author of How to Keep Your Teenager Out of Trouble and What to Do if You Can't, agreed with the study's implications, he told USA TODAY, arguing: "Extremes of parenting don't work. The put-down parent is no more effective than the laissez-faire parent who is totally chill and sets no limits on their children's behavior."

The study's authors explored more than the effects of harshness alone; they also measured whether “parental warmth," or the degree of love, emotional support and affection between parents and adolescents, counteracted the effects of verbal discipline -- and concluded it does not.

“Even lapsing only occasionally into the use of harsh verbal discipline can still be harmful,” Wang said in the study's press release. “Even if you are supportive of your child, if you fly off the handle it’s still bad.”

"Harsh verbal discipline deserves greater attention in both research and practice," the researchers conclude in the study's Discussion. "The majority of research conducted on harsh discipline has focused on physical discipline in early childhood. However, given that parents tend to resort to verbal discipline as their children mature (Sheehan & Watson, 2008), it is important that researchers and parents are aware that harsh verbal discipline is ineffective at reducing conduct problems and, in fact, leads to increased adolescent conduct problems and depressive symptoms."

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  • 1. If you want to talk to me about a problem, schedule a morning appointment, when I'm fresh.

    By the afternoon, I can get pretty frazzled. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 2. You're right, that teacher does stink.

    I'm actually in the process of firing her. Legally, I can't tell you that, though, so that's why I'm sitting here quietly while you complain. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 3. Of course I'm going to disapprove of a child missing class for vacation.

    What I won't tell you is that I encouraged my own daughter to pull her kids out of school to visit me during my break. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 4. We had a young man struggling to focus during year-end tests.

    "My underwear is on backward," he said. That's the problem with all this testing: We're being judged by assessments taken by kids who may have their underwear on backward. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 5. You think that what happens at home stays at home?

    We hear about your financial problems, your nasty fights, your drinking problem. We end up knowing way too much about everybody. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 6. The child you see at home?

    That's almost never the one we see at school. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 7. Don't tell me your child would never lie to you.

    All kids make mistakes, and great students are often the ones most afraid to tell their parents when they screw up. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 8. When we have a child who throws things or tries to hit when she's angry...

    ...her parents inevitably say, "I don't have a problem with her at home, because I spank her." <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 9. My biggest pet peeve?

    Parents who complain to me before talking to the teacher. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 10. Don't ask me to make a teacher forgive a homework assignment or not to teach a specific subject.

    We don't dictate to teachers; we work with them. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 11. I've had a few students who were bullies.

    We suspend them again and again, but it's very tough to expel a student. The truth is, they have a right to an education. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 12. Kids are easy.

    It's the parents who are tough. They're constantly trying to solve their kids' problems for them. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 13. What do I love about this job?

    I can influence and inspire kids and adults, help work through problems, and find solutions. And every day I can pop into a classroom where something interesting is going on. What other job gives you all of that? <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 14. C'mon parents, this is your child's homework, not yours.

    We know what a seventh-grader can do, and we know what an adult with an engineering degree can do, so please don't do your child's work for him. Kids need to make mistakes and struggle through things; it's how they learn. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 15. Principals never know what the day will hold.

    One minute you're mopping up vomit, the next you're in a special ed meeting, and the next you're dealing with two kids who got in a fight. Then you shovel snow off the sidewalk in front of school, you meet with teachers to decide whether to change the language arts curriculum, and you play basketball with a group of kids. And that's just in the first two hours. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 16.The last thing I want to do on the sidelines of a basketball game or during intermission at the school play is have a conference with you about your child.

    If you have something to talk to me about, come by my office during the day or even better, make an appointment. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 17. If you and your child don't like his teacher, tough luck.

    Think of it as a lesson: In school, as in life, sometimes you have to learn to deal with things you don't like. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 18. When an unruly student gets sent to my office, my favorite strategy is not to engage right away.

    I just let them sit there in agony while I keep working. It gives them a chance to calm down and de-escalate. Try it at home; it works. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 19. For years, folks have said that if you can't do anything else, you can always go into education.

    The truth is, we're not the leftovers, and this is what most of us wanted to do. I had been accepted to law school, but I chose this. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 20. Our favorite kids aren't necessarily the ones with the highest IQs.

    What we really value is hard work. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 21. Since the economy has gotten bad, it seems that more parents are taking any job they can get...

    ...working crazy hours and neglecting their children. Then a lot of them try to make up for that by coming to their child's rescue when there's an issue with a teacher, coming in here and hollering at us. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>

  • 22. As a principal, you're expected to know about bus routes, curriculum, communication, school lunches, adolescent development, conflict management, learning disabilities, and more.

    You have to be an expert on everything, sometimes in the same 20 minutes. <em>Credit: <a href="http://www.rd.com/slideshows/13-things-your-kids-principal-wont-tell-you/" target="_hplink">Reader's Digest</a></em>