I LIVE in a town with hundreds of restaurants serving many of the world’s cuisines: sushi bars, pizza parlors, pho, tapas, KFC, you name it. My family eats out a fair amount, and we appreciate these tastes, so we could conceivably explore a different menu every outing. But we don’t. Some years ago we discovered a neighborhood caf that we all really like, and that’s pretty much where we go. It is our place.

I know that other people are different. We’re basically opting for certainty and predictability, whereas others prefer exploration and change. But why do people differ on this trait? What motivates some to constantly seek out the next best thing, the greener grass, and others to stick with what is known and safe? How do we know there’s not a new and better favorite eatery just around the corner? Are we trading off curiosity and novelty for the luxury of not having to make a decision?

Psychologists are very interested in this question, and some believe it may reflect a fundamental difference in cognitive style, wired into our neurons. Think of it this way: our ancient ancestors had to forage in the savanna for food and water, but there was no telling where they would find these resources. The environment was patchy, with a watering hole here and an antelope herd there, but no uniformity or predictability. So what was the best search strategy? Once you find a hunting ground with some antelope in it, do you set up camp and make it your own, or do you go looking for a better hunting ground, then a better one still?

An Uncertain World
Now fast-forward to modern times. Our challenges are perhaps more intellectual and abstract, but we still have to decide how to deal with an uncertain world. Faced with a problem or decision or choice, do we bear down and exploit one idea for all it is worth, or do we move rapidly on from one solution to another to another? Or maybe we do both, depending on the problem, toggling back and forth until we find what works.

Indiana University psychologists Thomas T. Hills, Peter M. Todd and Robert L. Goldstone decided to explore these questions in the laboratory. They wanted to see if people do indeed have a consistent cognitive style for foraging, whether it is for food or for ideas. They also wanted to see if jostling those ancient foraging neurons—triggering either exploration or exploitation instincts—influences the way people approach modern problems.

Because they could not actually ask people to root around for food in the wild, they used some modern tools: a computer and a board game. They had a group of volunteers manipulate icons to “forage” in a computerized world. Volunteers could move around until they stumbled on a hidden supply of food or water, at which point they had to decide if and when to move on, to continue the search (and in which direction), and so forth. The scientists tracked their movements.

But the volunteers explored two very different worlds: Some foraged in a “clumpy” world, which had fewer but richer supplies of nutrients. Others explored a “diffuse” environment, which had many more but much smaller supplies. The idea was to “prime” the unconscious mind to use the optimal foraging strategy for each possible world. Those who looked for resources in a diffuse world would in theory do better to give up on any one spot quickly, moving on rapidly and navigating to avoid any duplication. Those in a clumpy world would be more likely to stay put, exploiting the rich lodes of nutrients rather than keeping up the search.

Scrabbling for Words
That was the first part of the experiment. Afterward, the volunteers participated in a more abstract, intellectual search task: the board game Scrabble. They didn’t actually play Scrabble, but they got letters as if they were going to play, and they had to search their memory for as many words as they could make with those letters. As with the board game, they could also choose to trade in their letters for new ones, but in the experiment they could do it whenever they wanted to. The wholesale trading of letters is what the psychologists were actually observing: they wanted to compare the volunteers’ Scrabble strategies with their foraging strategies, to see if they stuck with the letters they were given—or rapidly abandoned one set of letters for another (more promising) set. In other words, would those who were mentally primed for a clumpy world see their Scrabble letters as rich clumps, worth sticking with, whereas those primed for a diffuse world would quickly abandon one set of letters for another?

The results were striking. As reported in the August issue of the journal Psychological Science, those whose neurons were primed for exploration in the wild were also more restless and exploratory in Scrabble, whereas those primed for exploitation were more focused and persevering when they switched to the abstract mental challenge. Put another way, the human brain appears capable of toggling back and forth between exploration and exploitation, depending on the demands of the task.

The psychologists also found that individuals were consistent in their cognitive style. That is, the most persevering foragers were also the most persistent Scrabble players, just as gadabouts in the food search tended to gallivant in intellectual matters as well. And presumably in life: they would probably be too antsy to settle for a “good enough” neighborhood caf.

But dining out is trivial. These findings have more serious implications related to other recent work on brain chemistry and cognitive disorders. Exploratory and inattentive foraging—actual or abstract—appears to be linked to decreases in the brain chemical dopamine. Similarly, many problems related to attention—including attention-deficit hyperactivity disorder, drug addiction, some forms of autism, and schizophrenia—have been associated with a dopamine deficit. It is possible, psychologists say, that computer foraging might reveal one’s underlying cognitive style—either having persistence or lacking it. It is even possible that simulated foraging could have long-term effects on thinking style and possibly even lead to therapies for cognitive disorders. That is something worth exploring.

Note: This story was originally published with the title, "Foraging in the Modern World".