Editor's note: Mel Robbins, a CNN commentator and legal analyst, is the founder of Inspire52.com, a news and entertainment site for women, and author of "Stop Saying You're Fine," about managing change. She speaks on leadership around the world and in 2014 was named outstanding news talk radio host by the Gracie Awards. Follow her on Twitter @melrobbins. The opinions expressed in this commentary are solely those of the author.

(CNN) -- The only person you can legally hit in the United States is a child.

Hit your partner, and you'll be arrested for domestic violence. Hit another adult, and you'll be arrested for assault. But hit a 4-year-old, and you can call yourself a "loving father." That's completely screwed up.

It should be against the law for a fully grown adult to slap, hit, spank, punch, switch, whoop, whip, paddle, kick or belt a defenseless child in the name of discipline. But it is legal, and new research in the Journal of Family Psychology suggests that the average 4-year-old is hit 936 times a year.

If study after study conclusively proves that hitting your kids doesn't work as a disciplinary method, and worse, it has long-term damaging impact to their psychology and makes your kids more aggressive, why do we as a society allow it?

The comment sections on this topic are real special, so let's address them in advance:

1. I was hit, and I turned out fine. Kids are too soft these days!

I was molested as a kid, and I turned out fine too, but that doesn't mean I think it's okay to molest kids. The fact that you survived abuse doesn't mean you should be allowed to inflict it on your own kids.

Growing up in the Midwest, I was spanked. Getting spanked only made me do what all the research suggests: fear my parents and start lying to avoid getting in trouble.

Using other forms of discipline doesn't make kids soft, it makes parenting harder because you have to control yourself in order to keep control of the situation and use other methods to discipline your kids even though you want to hit them.

2. It's culturally acceptable to hit kids in the South.

Folks defending football player Adrian Peterson, like commentator and former basketball star Charles Barkley, want you to consider the Southern culture he grew up in. I find the "cultural" excuse appalling.

Barkley described getting "whipped" as a child in the South and having bruises and welts on his legs. Seriously? You were beaten as a child, so let's just carry it on, Barkley?

Let's just carry that to a logical conclusion. There was a culture of slavery and racial segregation in the South; does that mean we should carry it on now? Of course not. There's a culture of rape in India right now; does that mean it's OK to carry it on? Of course not.

There's a culture of hitting kids behind closed doors and calling it discipline in this country; does that mean it's OK to carry it on? Of course not.

It's 2014, not 1814. It's time for violence against children to be illegal, in all forms and all forums, regardless of the "culture" you were raised in.

3. According to Charles Barkley, if it were illegal, "every black parent in the South would be in jail."

It takes a lot to shift cultural norms, and the laws can be a very powerful tool in eliciting change. Ever wonder why most parents spank their kids behind closed doors? It's because deep down, they know it's wrong and don't want anyone to see it.

If parents feared jail time, they might think twice about doing it. Peterson didn't know he had gone too far until it was too late, like many parents. That's why we need to draw a very clear line between discipline and abuse.

And I can't help but wonder what the long-term effect on violence in America might be if we got serious about protecting kids from it in their own homes.

The United States has the highest incarceration rate in the world.

The Office of Juvenile Justice and Delinquency Prevention reports that "maltreatment and neglect" by family increases the likelihood of delinquency and violence in teens. I'd call hitting a 4-year-old almost 1,000 times a year maltreatment; wouldn't you?

To spank or not to spank?

4. The government isn't gonna tell me how to raise my child.

There's a simple reason why culture needs to evolve and physical discipline needs to become a thing of the past: Kids can't protect themselves, and most adults can't control themselves when they get frustrated and angry.

We as a society have an obligation to protect kids from violence. This isn't a liberal versus a conservative position or new school versus old school; it's about protecting kids. If you consider yourself pro-life, you better consider yourself anti-spanking, because protecting the sanctity of the child should apply to its life outside the womb as well.

5. The wussification of America continues.

Facing the facts doesn't make you a wuss. It makes you smart. The fact is, spanking doesn't work. In the Journal of Family Psychology study, kids were misbehaving within 10 minutes of getting spanked. It only helps the parent relieve momentary frustration and regain control and saddles the kid with long-term damage.

If you pick up a belt, a switch or a paddle and hit your kid with it, that's abuse. The only thing that guarantees children's success is helping them develop positive behaviors by modeling them, and the most effective methods are education, mentoring, conflict-resolution training and safety. "Get tough" approaches rarely work.

As for Peterson, I find it incomprehensible that he lost a 2-year-old son at the hands of child abuse when the mother's boyfriend allegedly beat the boy to death -- and less than a year later, police say, Peterson whipped his 4-year-old with a stick, causing cutting and bruising of the back, buttocks, ankles, legs and scrotum of his son. According to the police records, the boy was worried that "Daddy Peterson" would punch him in the face if the child reported the incident to authorities.

The child told his mother that Peterson "likes belts and switches" and "has a whooping room," according to police reports. He added that Peterson put leaves in his mouth when he was being hit with the switch while his pants were down.

The little guy also had "defense wounds" on his hands as the boy tried to protect himself from an NFL player with a weapon. Sick.

Peterson might be the best running back in the NFL, but he may be one of the worst fathers in the league. So let's all stop defending him and start defending the kids who can't defend themselves.

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