Using Variable Rewards to Drive Behavior Change

Easily distracted by shiny objects
Sound familiar to anyone?

There’s something thrilling about newness and uncertainty. Whether it’s watching a gripping Christopher Nolan film, starting the next level in a game or going on a first date, we can be easily captivated by what we don’t know.

The human species possesses a disposition towards novelty – and tens of thousands of years ago, that drove us to explore new lands, try new foods and see what happened when we struck two rocks together.

But just as our craving for sweets, salts and fats were valuable in the Paleolithic era, when such foods were scarce, but are now warped in the age of carmel-drizzled kettle corn, our novelty-seeking tendencies can lead us astray.

Variable rewards are a particularly powerful “hook” for the brain. Casinos and many games use frequent but hard-to-predict rewards to keep their players coming back for more.

In this post, I want to talk about how variable rewards work and how we can use them to drive positive behavior change for ourselves.

The science behind variable rewards

Variable rewards are when you positively reinforce a behavior at an non-fixed (ie less predictable) schedule. By varying when you deliver the reward for a certain behavior and how big that reward is, you can quickly reinforce that behavior and make it very strong and resistant to extinction (aka it becomes a habit or routine).

This finding is born out of the research conducted on animals, for instance: teaching a rat to press a lever. Researchers found that when compared to a fixed schedule (eg: a piece of cheese every other lever presses), mixing up the schedule (eg: two rewards in a row after one press, then a single reward after three presses, etc) was more effective even when the overall reward ratio was 1 to 2.

How Variable Rewards Work - Jason Shen
Quick chart I whipped up to explain the difference between fixed ratio and variable ratio rewards.

Why does this work?

The answer has to do with dopamine, a neurotransmitter that’s tightly linked with desire and habit. Getting a reward increases dopamine levels in your brain, which motivates you to do the thing which got you the reward (rats with missing dopamine receptors struggle to build habits).

But dopamine isn’t just pleasure, it’s about anticipation of pleasure. When we know how the game works (this lever press won’t give us a reward, but the next one will) our novelty seeking brains get bored. But when the rewards are unpredictable, we stay on edge. Studies have shown that unpredictable rewards cause greater increases of dopamine, which may be why the behavior that lead to the reward gets so strongly reinforced.

Let’s look briefly at how variable rewards has been applied in areas like casinos and games.

Variable Rewards in The Real World

Casinos completely understand how addicting variable rewards can be.

Slot machines are designed to pay out just enough to keep you wanting more,  stopping right before the jackpot symbol so it feels like you “almost” won, to get you to play again.

When playing card games like Blackjack and Poker, a big hand could be coming right around the corner, keeping you glued to your seat and in the game. Like the tobacco industry once did, the gambling industry rakes in enormous profits off the backs of highly engaged (and sometimes addicted) users.

I don’t condone the many of the practices of casinos, but I include this section to highlight just how powerful variable rewards can be in directing human behavior.

Many games also rely on variable rewards to boost engagement

Setting aside “gambling games” like Zynga Poker, most regular games have some element of randomness / unpredictability to them. From random item drops, to dazzling cut scenes which appear at an unexpected point in the game, to levels or enemies that change from round to round

Some directly incorporate gambling elements, like JetPack Joyride, a popular iOS game which allowed you to collect special bonuses that could be cashed in at the end of a round  literal spin the wheel bonus points during a particular round of gameplay, which can be cashed in for wheel spins. It turns out this is not a new idea – Super Mario Bros 2 was using the same tactic 18 years prior.

Using variable rewards to develop better personal behavior

I’m obsessed with positive behavior change and always looking for more effective methods of developing good habits and shedding bad ones.

A lot of people have set New Year’s Resolutions this year and data suggests around 40% will fall off in the first month or so. This is often because they are running on pure willpower, which is a limited resource and not enough on its own to drive behavior change. What about using variable rewards?

A personal story with variable rewards

In December of 2012, I decided to develop the habit of brushing my teeth at night. I used to brush my teeth in the morning and in the evening but sometime ago stopped brushing at night and I wanted to restart that habit. I decided to use variable rewards to help encourage the right behavior.

Every time I brushed my teeth at night I would check it off on the Lift app (though any tracking system works) and I gave myself a spin of the virtual roulette. I’d pick 4 numbers in my head, and if I “got lucky”, I’d buy an app or game on the App Store as a reward.

The way I had set it up, I would be winning every 10 spins. I think I scored my numbers two days in a row and that was totally thrilling. A month later, it’s pretty much a locked in habit. I think I only missed one night in the past 30 (and it was New Year’s Eve so rather understandable..)

I’m not the only one using variable rewards to change my own behavior. In doing research for this blog post, I found an article from The Guardian about a guy who had developed a system called Habit Judo which leveraged the same dopamine spike of a random point bonus that my roulette app did.

Tips on making variable rewards work for you

  • Start with one habit at a time – doing more than 1 or 2 can easily get overwhelming
  • Make your habit something easy and small that you can do every day – see BJ Fogg’s Tiny Habits for more on why this is effective
  • Making the rewards something that’s a genuine treat – yet affordable/easy to dole out
  • Try to give yourself the reward immediately – habits are formed in a deeper part of our brain that don’t work as well if the reward doesn’t happen till next week

We want to eat healthier, work out more, and check email less frequently. But it’s hard – there are powerful forces working to make you eat more, be lazier and browse the internet constantly.

Fight back by setting up your own systems.

If you want to learn more about how variable rewards can integrate with other scientifically proven principles for effective behavior change, check out my online class on The Science of Willpower, Habits and Behavior Change that starts JAN 15th 2013.

Thoughts, questions, feedback? I’d love to hear them in the comments.

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Jason Shen

Jason is a tech entrepreneur and talent expert. He is CEO of a performance hiring platform called Headlight, a Fast Company contributor, and an advocate for Asian American men. Follow him on Twitter at @jasonshen and subscribe to his private newsletter.

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  1. Great article. I’ve used variable rewards in the past by flipping two coins every time I logged an additional hour of work on high priority goals/projects. Whenever the coins landed as 2 heads, I would earn an energy drink (I crave those things, but usually don’t drink them). The system worked very well, to the point where I include some level of variable rewards in all major goals/projects I undertake.

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