Writes Free Your Kids:

The vast majority of humans do not hit those who may hit them back. Most men, even when terribly angry and enraged, will not hit another man because, in part, they fear being struck back. Same thing goes for women hitting other women (or men). Getting into physical altercations is not beneficial for an individual’s health, so they avoid it.

Yet, many people have no problem at all hitting something smaller than themselves. Men will hit women. Men and women will strike small animals. And, of course, both men and women hit children. Young children. Not larger, physically-stronger children (like teenagers) who can physically defend themselves. Young children. Toddlers. Babies.

The truth is, if children were physically larger and possessed the means to defend themselves, parents wouldn’t risk hitting them. Spanking would be nonexistent. No one would dare to physically punish someone who might retaliate by kicking them in the teeth.

That they are smaller, weaker, and relatively defenseless should be all the more reason not to hit them.