Human beings are creatures of habit. Certain situations cue us to behave in certain ways, and we expect the same behaviors to predictably give us the same results. This is called conditioning: we learn to associate a certain stimulus with a behavior, and the behavior with a reward. The reward motivates us to continue the behavior.
| Stimulus | Behavior | Reward | Consequences of the reward |
| You feel groggy and grouchy. | You drink a cup of coffee. | You feel better. | The next time you feel groggy and grouchy, you start craving coffee, because your brain knows it will make you feel better. |
| You see an advertisement for some kind of delicious food. | You buy the food and eat it. | Your brain’s pleasure centers light up and you feel good. | The next time you see an advertisement for the food, your mouth starts watering and you want it again. |
Don’t underestimate the power of this kind of habitual reward cycle. Many people find it extremely hard to switch to Paleo for good because they’re stuck in this kind of cycle with junk food. When they try to break the cycle, they get an extinction burst.
What Is an Extinction Burst?
Let’s say you have a habit of drinking coffee in the morning. You wake up feeling like death warmed over, you drink your coffee, and you feel better. This motivates you to continue drinking coffee in the morning. Now imagine that you try to quit coffee. This is “extinction:” you’re trying to cut off the reward and ultimately stop the behavior. Your mental conversation with yourself might go something like this:
If you’re trying to lick the screen right now, you might be in the middle of an extinction burst.
Brain: Coffee, please.
You: No, I’m quitting.
Brain: ahem. Coffee, please.
You: No.
Brain: COFFEE. NOW. RIGHT NOW. And if I don’t get it, you’re going to have this horrifying caffeine withdrawal headache forever.
If you don’t give it any coffee, your brain will eventually calm down and stop demanding it: that’s why it’s called an “extinction burst” and not an “extinction marathon.” But in the short term, when a familiar cue doesn’t lead to a habitual, rewarding behavior, your lizard brain responds by turning up the urge to do the familiar thing.
Scientists have studied this a lot in rats. Rats can be trained to self-administer nicotine or food by pressing a lever. When the levers are disconnected from the reward, the rats initially go a little bit nuts and start banging the levers like crazy; then they figure out that it’s not working and the lever-pressing behavior tapers off.
Not everyone gets extinction bursts. This study found that 39% of subjects showed extinction bursting behavior, meaning that around 60% of them never did. But for people who do get them, they can be absolutely awful to go through, especially with foot. Food is one of the strongest rewards around, and trying to quit a particular, highly-rewarding food (say, sugar) can trigger intense extinction bursts where cravings temporarily skyrocket when you stop eating it.
Extinction bursts (at least in humans, as opposed to lever-pushing rats) don’t always appear immediately after stopping the habit. Maybe for the first few days you’re riding high on your initial motivation and everything feels great…and then a week later when the first excitement wears off and your brain realizes that yes, you’re really giving up all that high-reward saltsugarfat junk food, the extinction cravings hit.
Alternately, maybe your cue for the behavior isn’t an everyday thing. A good example is people who eat for comfort. They might not have an extinction burst when they first go Paleo, but they might have one the first time they get really upset or stressed out, maybe a week or two after going Paleo in the first place.
People who study habit formation will tell you first and foremost to eliminate the cue that’s producing your desired response, or to associate it with another activity. But sometimes you can’t eliminate the cue (if your cue for drinking coffee is “getting up in the morning,” there’s no real way to avoid it…) and associating it with another activity doesn’t always work that well, either. Why not? Resurgence.
Extinction and Resurgence
Even if you make it through the initial extinction burst, the cycle isn’t broken. Even after you replace it with an alternate behavior, the initial behavior can still re-emerge after it’s been extinguished the first time. This is especially true if you reinforced an alternate behavior to replace the first behavior, and then have to stop the alternate behavior as well. For example:
- Joe Paleo knows that stress is a huge trigger for him to eat sugar. So every time he feels stress cravings, he goes for a run instead. Soon, he’s successfully re-trained himself to crave running instead of sugar when he’s stressed. Go Joe!
- Joe tears a tendon in his ankle and has to stop running for a while. Or maybe he goes on vacation, or starts a new job that interrupts his running routine.
- Unfortunately, as soon as John stops running to manage his stress, his sugar cravings come right back.
Resurgence of cravings for an “extinguished” behavior can appear for all kinds of reasons (changing contexts, changing stimuli, or apparently at random). Since extinguished behaviors don’t actually go away, a return to the reinforcement can put you right back at square 1. There are so many things in the modern food environment that trigger us to eat, and so many different contexts where eating is promoted, that it’s impossible to spot all the situations that might cause a resurgence in cravings.
Managing Extinction bursts and Resurgence
Plenty of people do manage to change their habits over their lizard brain’s objections – here are some tips.
- Plan for both, even if you hope they won’t happen. Make plans for managing cravings before you change anything, and make them easy to follow (the format “If I start craving ______, then I will do _______ instead” works well for many people).
- Pay attention to context. We change our habits within certain contexts, so watch out for different contexts (like going on vacation or visiting your parents for the holidays) that might create a sudden resurgence of habits you thought you’d beaten.
- Use habit change, not just habit extinction. The study above found that extinction bursts were much more common when extinction was the only method of behavior change and less common when it was implemented along with something else. Here’s a great in-depth explanation with practical strategies from Getting Stronger. Just bear in mind that even habit changes won’t necessarily get you out of resurgence free.
- Remember that caving to the extinction burst only trains your brain to keep dialing up the cravings to 11. If you give in when your brain turns up the signal, what your brain learns is that it has to really go nuts with the messages to “eat more sugar, right now.”
Even with resurgence and even with extinction bursts, it really does get easier with time when you stick with your good habits, so don’t let all this information turn you into a pessimist. Just plan for your lizard brain doing its thing, and then when it does, you’ll be ready to manage it like a pro.