Parents in this middle group might turn to Kazdin and his parenting interventions. I spoke with Kazdin about his unusual method. An edited transcript of our conversation follows.

Olga Khazan: Where do people get their ideas about parenting? When people have a kid, what determines the kind of parent they’ll be?

Kazdin: It’s not determined or dictated completely by one’s own parents. For example, most of the children who are abused do not go on to be abusive parents. On the other hand, some things are transmitted through two ways. One of them is modeling. There’s an enormous impact that modeling has on a person, and parents don’t often use that strategically or constructively. Things that parents model very often influence how children behave as children and adults. For example, the way that parents discipline their children is how children discipline their peers. For parents who are very sarcastic, a child will be very sarcastic with their peers, and so on. The more a child is hit by his or her parents, the more a child will hit his or her peers.

The other thing is, our brains are wired to pick up negative things in the environment. It’s thought to be very adaptive, from an evolutionary standpoint. If you have a partner, significant other, or a child, if they do 10 nice things, that 11th one that you didn’t like, you’re going to really be all over.

Now you start groping for the various options that there are. The ones in your repertoire are likely to be ones from one’s parents, and also likely to be ones from other relatives.

And this is dictated by one’s personality, too. So, for example, one’s personality might be a little, tiny bit more impulsive. Some are more extroverted, some are more introverted, and all this is also normal.

Something called “temperament” is a physiological predisposition that is evident at birth. So, for example, young children with a very adaptive temperament, if they don’t get fed right away, it’s no big deal. If a mother hands them to some stranger, they don’t start crying and pouting. These are just variations in humans that are quite normal. So that temperament also dictates how much [a parent] can take before you respond.

Or let’s say you’re one of those moms who have postpartum depression. If it lasts for very long, you really alter how you rear your child. You’re much less warm and affectionate.

[So] your mom and dad, one’s own personality beginning with temperament, the influence of one’s peers, other mothers and fathers, and then what we just said, stress. All those things can increase or decrease reactivity.

So you’re really desperate. You shout; you try to reason; you think you’re a wonderful parent. You think that you’re just the greatest parent in the world. You sit down and say, “No, we don’t stab your sister. She’s the only sister you have, and if you stab her, she won’t be alive much longer.” It’s always good to do that with your child, to reason, because it changes how they think; it changes how they problem solve. It develops their IQ, but it’s not good for changing behavior.