A hyperstimulus is a regular stimulus that has been cranked up to 11.

Fruits and vegetables naturally contain sugar, which we use to power our brains. Since fruits and veggies are part of the normal human diet, we crave sugar and find its taste pleasant.

Through selective breeding and technological refinement, we’ve produced artificially concentrated sugars that can be used to produce everything from candy to ice cream.

Fruit is a normal stimulus; ice cream is a hyperstimulus.

Running downhill is a normal stimulus; a roller coaster is a hyperstimulus.

Singing and dancing with your friends is a normal stimulus; a rave is a hyperstimulus.

Tea is a fairly normal stimulus; cocaine is a hyperstimulus.

TV and movies are both, obviously, hyperstimuli. Mediums like Twitter, with their endless supply of short bursts of opinion, are like the potato chips of the information world.

Even things that are not obviously hyperstimulating may be, because we humans are really good at producing more of what we like and more of what people buy. All domesticated foods have been selected for the traits we humans like in our food, not just sugarcane:

The domestication of the banana is the process that transformed fruits full of seeds into parthenocarpic seedless fruits that develop in the absence of pollination. The earliest archaeological evidence of domesticated bananas was dated to 7,000 years ago https://t.co/FHzi7Ehg79 pic.twitter.com/qBOvdL3HHN — Massimo (@Rainmaker1973) February 23, 2020

(Just look at that wild banana!)

Do people click more often on headlines that say “Doctors recommend avoiding this one food to lose weight?” or “Local Grandma invents miraculous weight loss cure!”? Whichever one they click, proliferates.

What are the most popular novels? Thrillers and romance. (If you want to break into publishing, write a romance–they’re shorter than thrillers and Harlequin needs a constant stream of them.) These genres are fundamentally about producing strong emotions (and as far as I know, barely existed before WWII).

What’s wrong with hyperstimuli?

They aren’t inherently bad. One piece of candy will not kill you. Neither will one ride on a roller coaster. But a diet that consists entirely of candy will kill you. Even a diet that is merely 20% candy will probably kill you.

It is very difficult to avoid hyperstimuli because they excite stimulus pathways that we evolved to tell us when we have encountered something good, like fruit. It is very difficult to become addicted to something you are not already biologically predisposed to like: if some mad scientist invented jelly beans that taste like raw sewage, most people would have no problem avoiding them. By contrast, it is very easy to become addicted to something that excites all of the “this is good!” signals in your brain, even if that thing is actually nothing more than the specific chemical that signals “this is good.”

Normal stimuli, like fruit sugars, exist in a “whole package” of other things that are also good for you, like the rest of the fruit. Your desire for fruit sugars would normally lead you to eat the rest of the fruit, since most of us don’t have the required equipment for sugar extraction in our kitchens. Sugar, packaged and eaten with the rest of the fruit, is good for you. Your brain runs on the sugar, the fiber cleans your guts, the proteins build muscles, the fats can be burned for energy now or later, etc.

Refined sugar products contain much more sugar, per ounce, than your body is really designed to handle. You did not evolve to eat Froot Loops, no matter what your kids or the toucan on the box may tell you. And if you eat Froot Loops, you effectively crowd out other, more nutritious foods–or you have to eat twice as much to get the same nutrients.

Humans have gotten really good at eating twice as much, but not everything can be so easily doubled. If you watch TV instead of socializing, that time is lost. If you rack up wins in your favorite video game instead of challenging yourself to develop a skill in real life, that time is lost. If you do drugs, well, we all know how that ends.

And I think there is, similar to the tolerance people eventually build up to psychiatric medicines and alcohol, a kind of adjustment that we eventually make to stimuli. We get used to it. The noise we used to find chaotic and distracting, we just tune out. The music that used to excite us grows dull. Spicy salsa becomes bland as we seek the newer, hotter peppers.

I’m not sure the solution is to “cut the hyperstimulus out of your life.” We are basically stimulus-response machines that produce new stimulus-response machines; long-term stimulus deprivation drives us insane. But neither can we thrive, it seems, in high-stimulus environments (I define “thrive” here as an ecologist would, based on how many healthy offspring a community raises to adulthood. First world nations are basically dying by this standard.)

Striking the right balance is tricky. Some things, like heroin, clearly should not be in your life. Others, like candy, are harmless in small quantities–maybe even good. TV/internet/video games are mixed–they’re probably okay in small quantities but unlike candy, it’s difficult to obtain them in limited quantities. At the very least, you probably shouldn’t get cable and should set hard limits to the time you and your kids spend staring at screens every day.

So stop reading this post and go outside.