The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness

by Jonathan Haidt

The loop starts with an external trigger, such as a notification that someone commented on one of her posts. That’s step 1, the off-ramp inviting her to leave the path she was on. It appears on her phone and automatically triggers a desire to perform an action (step 2) that had previously been rewarded: touching the notification to bring up the Instagram app. The action then leads to a pleasurable event, but only sometimes, and this is step 3: a variable reward. Maybe she’ll find some expression of praise or friendship, maybe not. This is a key discovery of behaviorist psychology: It’s best not to reward a behavior every time the animal does what you want. If you reward an animal on a variable-ratio schedule (such as one time out of every 10 times, on average, but sometimes fewer, sometimes more), you create the strongest and most persistent behavior.