Studies have shown that hitting children makes them more aggressive, is ineffective, and has lasting long-term negative emotional effects. Evidence also suggests that children who are spanked have lower IQs.
The main reason against corporal punishment seems to be that studies say it leads to aggression in children. Even if children are not hit regularly or hit hard, evidence suggests that when they are smacked by their parents they are learning to equate violence as a solution to problems. However, there are other negative effects of smacking that are also serious. Smacking can lead to lower intelligence.
Another problem with spanking or smacking is that it is ineffective. It simply does not work. In other words, it does not curb the behavior you are trying to prevent. In addition to that, it has lasting negative emotional effects. Children might suffer depression or low self-esteem. Spanking also relies on the parent to have quite a bit of self-control. Parents often say that they only hit their child a few times, and not very hard, and they are not angry and in total control. However, anyone who has dealt with a child knows how they can push buttons. Quite frankly, it is easy to step over the line. Spanking can lead to abuse very quickly.
Once the child and the parent get into the cycle of misbehavior and spanking, it can be difficult to get them out of it. Spanking may be an easy solution to the problem for both of them, but it is not a good one. They are not addressing the problem. Neither of them is talking. There is no communication, and no verbalizing going on. It is easy to see how this can lead to lower IQs and increased aggression. Teaching children to talk things out and use their words is much more complicated, but much more effective and leads to better relationships in the long run.
Smacking children does not show any real, long term benefits and really is just cruel. When a child is smacked often in a household it emotionally scars the child and scares them more than teaching them a lesson. A better way to teach a child that something is wrong is to tell them and show them through your own behavior. Smacking a child will make them think it is ok to hit people, for example their future children, because you are doing it. Children learn from their parents and if you think smacking is ok, they will. If you hit your children they will become scared of you and be scared of doing the wrong thing or making mistakes. Smacking should be banned for these reasons and probably many other reasons.
Smacking does not help or encourage a child. it simply terrifies the child,in some cases to the point where they are too scared to try simply because they are scared they will fail and will get smacked for failing. smacking is a way of telling your child its okay to hit people when they are wrong, which its not. It also enforces the fact that its not okay to fail its not okay to make mistakes and puts pressure on the child to be perfect at all times. I agree with the answer above that it increases the amount of violence in the child maybe not towards the parent, but towards other kids. as a child who grew up in a strict school in india where smacking was allowed, i have seen guys, who were more prone to punishment, get in more fights rather then the children who did not.
In some cases, smacking does work, depending how the parent(s) follows up after and depending on the words used during the time of discipline. But since you are asking for an argument that goes against smacking, here is this:
Smacking, if done unwisely and if especially done impulsively, will harm the child emotionally more than physically. Physically, it does give pain and if done too harshly can damage something. But emotionally, children will never forget a slap. Children will hold it in their memories and hearts as they grow up. It also ruins the image of the parents for them. They begin to see their parents as mean and bitterness against parents will develop because children may not understand the concept of discipline or the motive behind parent's spanking.
If a child is the type to react badly after, he or she can react by being more disobedient, arguing back, failing in school, being less social, throw hurtful words back to the parent, or even being violent toward the parent. The reactions to smacking are all dependent on the uniqueness of the child. But generally, if a child reacts negatively toward smacking, these things can happen.
Scientifically, children will be more aggressive, and is harmful to the emotional health of the child.
In terms of parenting, it is more important for the parent to set an example then to spank the kids for doing something wrong. Children have been shown to learn more about the ways of life more effectively when they follow examples. Similarly, if a parent sets a bad example, the child will likely copy it.
Fundamentally, spanking just does not work.
Hitting children is fairly hypocritical of us to do so as a form of discipline or punishment. When a child hits or hurts another child, we want them to understand that is wrong. Hitting them back is not only ironic, its pointless. Children learn through example and imitation. We need to set good examples.