David Solot is a Ph.D. student in organizational psychology at Walden University, with a Masters in clinical psychology. His background includes the study of animal sensation and perception, and conditioned responses to sweetness in foods.
Is there a food you just don’t like, and you can’t explain why? Or perhaps a food that made you sick once, and now you can’t come near it? It could be the result of a million-year-old survival mechanism.
When I was about six years old, I started hating cherry Jell-O. There was no apparent reason for it. I liked cherry Kool-Aid and shaved ice, and I was fine with other flavors of Jell-O. But the sight or smell of cherry Jell-O would instantly make me nauseated.
My reaction to it was so bad that my parents used to tell people I was allergic to it, just to avoid my reaction. They even wrote it down under “allergies” on a school form. I just couldn’t touch it without feeling sick.
Perhaps you feel the same way about raw tomatoes, yogurt, or eggs. If there’s a food that makes you feel sick on sight, chances are that your brain is enacting a behavior that’s been passed down for millions of years. It’s called taste aversion, and it’s one of the strongest conditioned reactions in humans.
Here’s how taste aversion works: You and your buddies go out for a few drinks. You’re young and wild and love drinks with the strong coconut flavor of Malibu Rum. Things get a little out of hand, and you spend part of the night praying to the porcelain god. You recover, and next weekend go out for drinks again. The bartender passes you your favorite drink, but this time the smell of coconut immediately makes you want to vomit. You loved Malibu for years, but now, the very thought of it makes you sick.
What you’re experiencing is your brain protecting you from being poisoned. When we were primitive creatures, we weren’t sure what was safe to eat so we tested things out.
If you survived the experience, your brain had to make sure that you never ever ate that same thing again. So, if you ate something that made you feel ill, your brain decided “better safe than sorry,” and conditioned you to feel sick anytime you saw, smelled or even thought about that same food.
The next time you went foraging for food and came across a berry that made you feel sick in the past, you would get hit with an overwhelming feeling of nausea and go eat something else. The people who were good at developing taste aversions lived and had children. The ones who were bad at it – well – they largely got poisoned and died. So over the centuries, our ability to form taste aversions got stronger and stronger.
The reason your night of drinking resulted in a hatred of Malibu is due to this same survival mechanism. When you felt nauseated at 3am, your brain sensed that you had been poisoned. Your brain didn’t know for sure what caused it, but it did remember a really strong coconut flavor from earlier that night.
To protect you, your brain decided “better safe than sorry,” and assumed that the coconut flavor was to blame. To make sure you don’t poison yourself in the future, it set up a conditioned response so that the smell or taste of coconut will make you feel sick.
That’s how taste aversions work properly – you no longer want to eat the thing that made you sick. But it can get more complicated than that.
You may find that you suddenly hate coconut shavings on ice cream. A year later, you may push away a plate of coconut-battered shrimp at a restaurant, and have no idea why you find it so repulsive. Taste aversions are just that powerful, and they can last for years after only one bad experience.
To make matters more confusing, sometimes aversions form for the wrong food. Imagine that on the way to work one morning you stop off for your traditional cup of coffee. Later that day, your coworkers all go out for Indian food. You’ve never had Indian food before, but you’re up for something new. You have a delicious meal and try lots of new items. But around 3pm, you start feeling queasy. It gets worse and worse, and by the evening you’re sick to your stomach and not able to hold anything down.
Your brain senses that you’ve been poisoned. Once again, it isn’t sure what did it, but it does remember a lot of strong spices and flavors that it never tasted before. To make sure you don’t poison yourself in the future, your brain decides “better safe than sorry,” and conditions you to feel sick any time you smell, taste or even think about Indian food.
The problem is, it turns out that there was nothing wrong with the Indian food – it was the creamer in your morning coffee that had gone bad! “No way,” says your brain, “we’ve had that coffee every day for a year. We know that it’s safe. It had to be that weird new food we ate.”
Suddenly you have a strong aversion to Indian food, even though it tasted good and there was nothing wrong with it. To make matters worse, you’ll probably never know your hatred of Indian food is irrational, because you don’t know that the real cause of your illness was your coffee. You’ll likely think that Indian food makes you sick and avoid it in the future.
This kind of thing is happening to us all the time, and we’re mostly oblivious to it. Have you ever had a really bad cold, and decided to make yourself feel better by eating your favorite food? You might find a few days later that you’ve stopped liking your favorite food. That’s taste aversion in action! Your brain assumes that the illness was caused by the food, and is teaching you to not like that food any more.
This effect is so strong that people undergoing chemotherapy (which can cause severe nausea) are cautioned to avoid their favorite foods. You might think you’re comforting yourself, but what you’re really doing is teaching your brain that “favorite food = feeling sick.”
Luckily, our conscious minds are mostly able to overcome this effect. The key is to recognize what is happening and to think about the reason for the reaction.
Consciously reminding yourself that what you’re about to eat is not poisonous can help you to interrupt the automatic survival mechanism. With practice, you may find that you are able to stomach the foods that used to hate. You may even start to like them again.
The key is to go slowly, and expose yourself to the food in positive surroundings. Teach your brain that there’s no connection between the food and feeling bad.
As for my cherry Jell-O aversion, I remembered that back in kindergarten I was served room temperature cherry Jell-O and whipped cream, all swirled together. I got sick to my stomach, and that’s when I started hating it. By thinking about the cause of my reaction, I was able to teach myself to enjoy cherry Jell-O again. But if I put whipped cream on it, I still get a little queasy. A million years of evolution is hard to overcome!