From Fruit Trees To Slot Machines: How Evolution Made Gamblers

Today, many people find thrills by sitting in front of a slot machine, watching the reels go round and round, hoping some matching fruit will fall into the right places.

Go back a few million years, and our evolutionary forebears did something incredibly similar — they also hoped some fruit would fall into the right places. Namely, their mouths.

Of course, the big difference is today, getting “bad” fruit on a slot machine won’t kill you. But if you were to come across some weird-looking fruit you never saw before back on the savanna, well, some of us would pass it on by, some of us would bring it back to our pals, and some of us would say, “Screw it, I’m eating it, let’s see what happens.”

Guess which one of those has evolved into the modern gambler.

“From an evolutionary, Darwinian kind of perspective, [evolution] favored those who had the best predictive systems,” said Dr. Mike J.F. Robinson, a Concordia University psychology professor who concentrates in behavioral neuroscience. “The better people were at predicting, the more likely they were to avoid foods that might kill you, know where to hunt foods, know which berries to pick that would not kill you.”

And while the example above is not precisely 1-to-1, it’s not that far off, either.

“We have a system that’s wired not just to seek out food, not just to seek out mates, not just to seek out shelter, but also to seek out the reduction of uncertainty and unpredictability,” Robinson said. “Because if we can reduce uncertainty, if we can address the unpredictable nature of events, then we’re increasing our survival options.”

And while nobody is confusing sports betting or roulette or poker with actual, life-and-death survival, the psychological mechanisms developed over millennia to keep us alive also — for some of us — make us want to gamble. And it also makes some of us prone to having trouble with gambling.

In short: Whether it be fruit in a tree or fruit on a slot machine, we are hard-wired to seek out patterns and reduce uncertainty. Only problem? There are no a lot of patterns — no matter how hard we try and find them — in gambling. And there’s a whole lot of uncertainty.

The fallacy

I never feel more dumb than when I’m on a gambling downswing and I find myself placing a bet, or waiting for the river, or tapping the spin symbol on a slot, and hearing my inner voice say the most misleading and flat-out wrong words in the gambler’s lexicon: “I’m due.”

Fact is, I’m not due. Just because I had some near-misses and just-maybes does not mean, in any meaningful way, that I’m “due.” That coin that came up heads five times in a row? Not “due” to come up tails.

And despite knowing this intellectually, it’s damn near impossible to turn off. My brain is seeking patterns where no patterns exist.

This is known as the Gambler’s Fallacy, and Dr. Jim Lyons of McMaster University set out a decade ago to see why it’s so prevalent — and why it’s so hardwired.

Lyons conducted two related experiments. In the first experiment, participants watched two targets that would light up in a random sequence. They were given money to place bets on which target would be illuminated next. The results showed that while participants kept their bet amounts consistent regardless of wins or losses, they tended to switch their bets to the other target after winning.

In the second experiment, participants performed the same task but with a partner. The pattern remained similar — players maintained consistent bet amounts regardless of outcomes. And when participants observed their partner successfully predict a target, they were more likely to choose a different target on their own subsequent turn. This suggests that people’s target selection was influenced not only by their own outcomes but also by observing others’ successful predictions. This is called the “inhibition of return (IOR)” effect, in which people are slower to return their attention to a previously checked location.

Now, let’s look at this via our old fruit tree.

Even when players hit the jackpot and correctly guessed which target would light up, they didn’t double down on their winning pick. Instead, they did what our ancestors might have done when finding a fresh patch of berries — they moved on to the next bush. This same behavior showed up when participants played with partners.

If their buddy struck gold by correctly calling a target, they’d avoid that same target like it was, well, yesterday’s fruit. It’s almost as if our brains are hardwired to think “well, that spot’s tapped out, time to try somewhere else,” even when dealing with completely random events. 

“It goes back to these sorts of search strategies,” Lyons said. “If you’ve been successful in one place and been rewarded for going there, you’re gonna try it again a couple of times until you find out there’s nothing else there, and then you’re gonna go someplace else.”

Perhaps even more interesting: People more susceptible to the IOR effects in the study — i.e., people who quickly changed their “bet” of where the light was going to go — were also more susceptible to gambling fallacy beliefs. 

“People can have a maladapted idea that they can control their environment,” Lyons said. “The problem comes in when you’re trying to control something that is objectively uncontrollable.”

Problems with gambling

Keith Whyte knows from uncontrollable. 

As the longtime executive director of the National Council on Problem Gambling until very recently, Whyte — who is neutral on gambling — has seen the problems it can cause for some people.

And Whyte is a firm believer that evolution plays a major role when it comes to problem gambling.

“We’re predisposed to spot patterns in nature even when they’re not there. That’s the evolutionary adaptation,” Whyte noted. “Everything in a billion years of evolution has taught us that it’s better to err on the side of spotting that pattern than to not spot it. For example, if you spot a leopard in the forest, you avoid it and your genetic material carries on. But what happens if you spot a pattern that you think is a leopard but it’s not? Well, there’s no cost to that because you still don’t die.”

And when it comes to gambling, those pattern-spotting techniques are tough to turn off. This tension between our conscious understanding and our evolutionary programming makes gambling particularly challenging for the human brain to process rationally.

“We’re not wired well to deal with what we’re dealing with when it comes to gambling,” Whyte said.

Although, to be fair, it also depends on the type of gambling.

For example, for a sports handicapper, there may actually be patterns out there that would yield — ahem — fruit. For example, how does an NFL team fare against opposing tight ends when the No. 1 receiver is out with an injury? There may be a pattern there. Or how does a certain power hitter do against fastballs away thrown between 92 and 95 miles per hour? There may be a pattern there.

And if you’re a poker player — or playing another game of skill — you can certainly attempt to spot patterns in your opponents’ behavior, and that could also be a very, yes, fruitful endeavor.

But … there’s certainly no pattern when it comes to slot machines. Or the roulette wheel. Or virtually every other form of random chance that is patternless, yet designed to appeal to our desire to spot a pattern.

“There is something in us that wants to try and understand the world around us,” Robinson, the Concordia professor, said. “Biologically, there’s an evolutionary purpose for us to be the best predictors of our environment as possible. There’s an intrinsic value in becoming perfect predictors.”

And again, this ability — and desire to hone it — has served us well. There was an obvious evolutionary purpose for humanity, and it took a handful of risk-takers in a group to make sure their DNA got mixed in with the more cautious individuals.

Fast-forward to modern times, and this evolutionary tool can certainly be seen as an explanation as to why some people are more prone to gambling than others.

Today’s gambling world — particularly casino games — exploits this evolutionary trait by creating environments full of cues and patterns that our brains instinctively try to decode and predict, even when there is no actual pattern to discover.

“We’ll have people who have high attraction to that uncertainty, and they’re the ones who are gonna be at risk, right?” Robinson said. “Then we have the majority of people who are going to be in the middle ground, and they’re like, ‘Hey, I find this rewarding, but I’m not going to lose my cool.’ Then there’s the people who find this part of life the single worst part of their day.”

Those people are sticking with apples, happily. As for me? Well, I’m still going to reach for a durian.