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Scarcity’s Effect on the Brain: Why Empty Shelves Make Us Dumber

Updated: Mar 29, 2020

Authors Note: This is the first in a new series of articles I’m calling Life & Death Design: Pandemic Edition which uses neuroscience, psychology, anthropology, macro-economics and other nerdy takes to unpack the unusual behaviors we are observing in ourselves and others during the COVID-19 outbreak. It is my hope that understanding the “why” behind our emotions and actions will reveal ways to make the best of this terrible situation.

I keep seeing images of empty store shelves show up on my social media feed. Every time another one pops up, I cringe. I’ve been studying human behavior in life and death situations for a while now and one thing that comes through loud and clear in my research – scarcity is a big trigger for bad behavior. The more we see it, the worse our decisions get.

The human brain is wired to take scarcity very, very seriously. When we believe we are in a situation where we won’t have enough supplies to survive we unconsciously reroute enormous amounts of processing power to think about addressing that issue. It becomes difficult to focus on anything else and it has a serious degrading effect on our decision making.

Studies by researchers at Princeton University showed that folks who are preoccupied with a lack of resources “exhibited a drop in cognitive functions similar to a 13-point dip in IQ, or the loss of an entire night’s sleep.”

In 2010-11, a team tested the effect of scarcity on the cognitive abilities of sugar cane farmers in India. These folks are unique because they get a huge pay out at harvest and then they have to stretch that big payday throughout the year. Because of this payment method, these farmers are in a “rich” mindset just after harvest and in a “poor” mindset prior to harvest. Researchers tested the cognitive abilities before and after the harvest and found that they performed far better when resources were abundant than when they were slim.

One of the author’s of the study, Jiaying Zhao said in an article published by Princeton, “These findings fit in with our story of how scarcity captures attention. It consumes your mental bandwidth.”

I don’t know about you, but between running a home school for my 3rd grader while still trying to get a full day’s work done, I don’t have much bandwidth to spare these days. Which is why it’s so taxing to see photo after photo of empty shelves show up on my social media feeds.

These types of images signal a survival threat which floods our brains with cortisol, the neurochemical most strongly associated with the human stress response. Cortisol actually has a wide range of effects on our brains:

  • Helps us make faster decisions, but this means we are also giving less careful consideration to those decisions

  • Pushes us to see things in black and white, reducing creative thinking and problem solving abilities

  • Makes it hard to understand and learn new things

  • Makes it harder to retain the things that we do learn

  • Increases our aggression, which makes us less likely to compromise, cooperate, or listen to reason

In other words, cortisol degrades our decision making process. This is why otherwise perfectly rational people suddenly decide they need 17 packs of toilet paper when they see that that is all that is left on the shelf.

The fact of the matter is, hoarding has nothing to do with rationality. Brain imaging studies imply that the parts of our brain that are responsible for our hoarding tendencies developed in mammalian brains long, long before our logic centers, and in a completely separate part of our brain. When the hoarding instinct is triggered it’s because the cortisol has come in and circumvented our normally rational decision-making process, pushing us to make fast, and often rash, decisions. In the right circumstances, pretty much anyone can be overwhelmed by this ancient instinct. The higher our stress, the more likely we will be to succumb to the impulse.

The other component of hoarding is human’s susceptibility to “herd” behavior – we see everyone else doing an unusual activity, assume they know something we don’t, so we start to do it as well. Again, this behavior is routed in ancient survival techniques. In a hunter-gatherer society acting as a cohesive unit, even when you weren’t fully informed as to what was going on, helped everyone survive. The fact that our ancestors who behaved this way survived to pass on that trait is why we still have it inside of us. So when we see everyone else loading their carts with paper products, our instincts tells us to follow their lead.

But what worked for small tribes can quickly spiral out of control when on the scale of modern society. During the gas shortages of the 1970’s journalists noticed a peculiar behavior. Drivers who would drive by long lines of cars queued up to get gas would often feel compelled to get in that line, even though they had plenty of gas in their tank. Richard Bianchi was interviewed while waiting in a half-mile long line in New Jersey with a gas tank that was three-quarters full. He couldn’t rationally explain his behavior, “I just want to have it, because you don’t know how long this is going to last.”

And now, fifty years later, I am hearing almost the exact same thing come out of my husband’s mouth. He went to the store with a list meant to get us through a week’s worth of sheltering in place, and he came back with an SUV so stuffed with provisions he even had bags of food piled in the front passenger seat.

When I asked him about his trip he shared, “At first, there was so much produce, I thought, ‘This isn’t so bad at all.’ But when I turned the corner, all the meat was gone. The shelves were nearly empty, the butcher’s case wiped clean. There were only a few packages on the shelf and I just started grabbing anything left,” he admitted. “I just thought, ‘You know what? I’m going to get some extra, because I don’t know what’s going to happen.’”

The key phrase echoed in both of these quotes is “because I don’t know.”

The human brain HATES uncertainty. When we can categorize something, even if it is categorically terrible, we can compartmentalize it and set it aside to focus on solutions. But when something is uncertain, our brain will return to it over and over, trying to give it a proper designation. It consumes an enormous amount of mental energy, stealing it away from all the other things we are trying to deal with during this crisis.

Everything about the coronavirus is rife with “unknowns” and that’s why it’s so hard to set it aside to deal with everything else on our plates. And those empty shelves… “you don’t know how long this is going to last.” It’s so compelling to that part of our brain that craves certainty and safety to stock pile those supplies.

A world-wide, high-stress situation like the coronavirus outbreak just is going to trigger this type of behavior in all of us, but we aren’t powerless. I'm happy to be able to leave you with some research-backed ways to avoid hoarding behavior during your next supply run.

  1. Make a list – Have a plan and stick to it. In these extreme times, it’s probably smart to write down exactly how many of each item you need so you aren’t making that decision in the moment.

  2. Go while you are well fed and well rested – Hoarding is largely an issue of impulse control. The more tired or depleted your mental and physical resources are when you go shopping, the less will power you will have available to fight those impulses.

  3. Order for pick-up or delivery – One of the biggest triggers for hoarding behavior is seeing empty shelves or other people hoarding. Take that out of the equation by not seeing others at all.

  4. Bonus Round: Post pictures of full shelves on social media - Consider posting photos of your own shopping trips if you find sections with plenty of good food. I hear produce aisles are bursting in most stores and they make for gorgeous, colorful pictures. Our mammalian brains are very visual and strongly biased in favor of believing people we consider part of our personal circle. This is one way to use the power of social media for good!

About the Author

Katie Swindler is a user experience strategist who writes and speaks on topics related to human-centered design. She is currently working on a book about Life & Death Design set to be published by Rosenfeld Media in 2021. If you’d like to be notified about her work please subscribe.


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