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My friend ‘Sara’ sent me this Facebook message the other day.

Her beautiful, precocious daughter was about 20 months old, and she was insanely obsessed with watching videos of Minnie Mouse. She would ask all day for “Minna, minna,” and cry when her parents said no. Sara knew I could help because I’m working on a book about the topic.

The first point that I made is that my friend isn’t doing anything dangerous or bad. The American Academy of Pediatrics has amended its “no screens before 2” rule. Up to 30 minutes a day with technology is probably fine even for very young toddlers, as long as they have no glaring behavioral, developmental, or sleep issues (too much digital media can interfere with all of the above). Starting around 15 months, with parental supervision, some studies show kids can even learn some things from educational media.

Still, Sara and her husband had a problem: a kid who asked for the phone all the time, cried when it was denied, and cried or got angry when it was taken away. Theirs is a pretty common situation.

Parents hand over the phone when we need a break, because it works! But “Mommy and Daddy need a break” is not a consistent, enforceable limit. It’s completely opaque to little children. So they’re going to keep asking for what they want, not knowing when you are going to say yes. What you’re creating is a situation behavioral psychologists call “intermittent reinforcement.”*

Here’s what I told Sara to do.

Decide when you really, really need a break.

It could be in the car, when you’re making dinner, or getting ready in the morning. Ideally it’s no more than once a day for up to 30 minutes.

Communicate that limit.

“Minna is for when Daddy is cooking.”

Enforce that limit.

I told Sara that at first it may be necessary to put her phone away for a few days when she’s parenting. That’s because every time she takes it out, her daughter is in the habit of asking for it. After a few days, she’ll just need repeated reminders.

That’s pretty much it. I ran into Sara a couple of weeks later at a birthday party, and she said that the problem had gotten a lot better. There were less tears and fights at home, and the whole family was feeling a lot less frustrated.

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*Psychologists know that intermittent reinforcement is by far the hardest kind of conditioning to extinguish.

Regular reinforcement works like this: If you give a pigeon a food pellet every time it presses a lever, it will become conditioned to press the lever. But once you stop providing the pellets, the rat quickly stops pressing the lever.

Intermittent reinforcement works like this: If you give the pigeon a pellet randomly, averaging, say, every 4 times they press the lever, you can take the pellets away forever and they’ll keep hitting the lever, trying their luck, ‘til they literally die of exhaustion.

Originally published at medium.com