When I asked her what she was doing to teach him how to behave, she grinned and pulled a man's belt out of her purse saying "I use this -- so does his father. We're not together, but I sent him over to visit his father yesterday so his father could beat him because he got suspended from school."

What I have learned over the years is that virtually all parents of angry adolescent youths keep the tools of discipline handy -- the belt in the drawer, or the paddle hanging by the kitchen door, ready for instant action.

After seeing more than 3,000 juvenile delinquents, I can now say with absolute certainty that:

1. Contrary to popular belief, delinquents are never found in permissive families. The more aggressive a delinquent is, the more likely he was beaten with a belt, extension cord, board or a fist.

2. As the severity of punishment in the delinquent's developmental history increases, so does the probability he will engage in violent acts.

3. Chronic aggressive offenders who were never hit with a belt, board, extension cord or fist are virtually non-existent.

4. Children who were born with behavioral disorders (such as hyperactivity) are hit the most and have the highest probability of becoming delinquent.

5. Most wife-abusers were beaten children; the most aggressive wife-abusers also witnessed their mothers being hit.

Since our research is often unsettling to parents who believe in spanking children, or were hit themselves, they frequently say to me, "Well, I was raised on the belt and I turned out fine; I've used the belt on all my children, and they're doing fine too."

Unfortunately, using a small sample as evidence for a theory is dangerous business.

Most children raised on corporal punishment turn out fine, but the risk of the opposite is clearly there. Corporal punishment is like a poison; a little bit of it may not hurt you, but who needs it?

In our studies, we found that physically over-punished children who in many respects appear to be responsible, functional members of society, also exhibit insensitivity and irritability; bad tempers and premature heart disease. (We now know that the Type A personality most prone to heart disease is the one with a lot of hostility engendered by early and excessive physical discipline.)

They exhibit depression (anger turned inward), over-aggressiveness toward their own children, behavioral inflexibility and use of alcohol and drugs. They are more likely to be school dropouts.

Although corporal punishment can at times, temporarily derail misbehavior, its long-term consequences are clearly negative.

A child is like a fine watch; sometimes a good whack can make it work temporarily, but it has the potential to permanently damage the fine mechanism.

For those who are still unconvinced that corporal punishment produces violent teen-agers, try tying up a dog (especially a potentially aggressive one like a Doberman or a Pit Bull) and beat it regularly. In time you'll have an attack dog. Do we really want attack children?

There are a thousand-and-one alternatives to physical punishment for changing behavior -- techniques, by the way, that are a whole lot more effective in making bad kids good.

Dr. Welsh is a clinical psychologist practicing in Bridgeport, Connecticut.