The Secret to Building Healthy Habits

March 21, 2024

In 2001, a neuroscientist named Gregory S. Berns was studying the brain. He wanted to see if humans preferred predictable or unpredictable rewards. He got 25 adults and split them into two groups. He gave each group drops of liquid while scanning their brains.

Group 1 got a predictable reward. He gave them alternating drops of fruit juice or water every ten seconds.

Group 2 got and unpredictable reward. They got fruit juice or water at random intervals.

Here's the actual figure from the study showing how drops were given:

So what happened? Each group started with a strong dopamine response, but over time things changed.

Each time Group 1 got their predictable reward, their dopamine response decreased. The brain got bored quickly with the same reward over and over again.

Each time Group 2 got their unpredictable reward, their dopamine response stayed strong. The unpredictability was exciting, and kept the participants wanting more.

Here’s the wild part: It didn't even matter if the participants liked juice. Unpredictable rewards were enough to keep dopamine pumping at strong levels.

Why does this matter?

Over the last 9 years there has been a steady increase in people using habit trackers. Here's the data from Google trends since 2015:

I've personally used habit trackers to build better habits. I've found them helpful for getting started, but hard to sustain over the long term. This study about predictable rewards explains why. Checking off a habit tracker is perfectly predictable. It's the same reward every time. As a result, the good feeling of checking off a day wears out.

So what should we do? Get rid of habit trackers?

I don't think so. They're helpful. But we should try making our rewards unpredictable. Here are some practical things you can try:

  • Habit Tracking with a Twist: Use a habit tracker, but introduce random rewards. For example, roll a die after you check off your habit. If it's a 5 or a 6, give yourself a small reward. This unpredictability can make the process more exciting.

  • Random Reward Jar: Write down various small rewards on pieces of paper (e.g., watching an episode of a TV show, taking a long bath, eating a piece of chocolate) and put them in a jar. Each time you complete your habit, draw a reward. The randomness adds an element of surprise and motivation.

  • Rotate Your Environment: If possible, change where or how you perform your habit. For example, if you're studying or reading, switch between different rooms, cafes, or parks. The new environments can keep the habit fresh and engaging.

If there's a healthy habit you've been struggling to build, try surprising your brain with unpredictable rewards. It might be the key to making that long-term change you've always wanted.