It’s not because you drank too many beers in the sun, or because the American education system has programmed you to stop thinking between Memorial Day and Labor Day. No, there’s a scientific reason for why we’re all a little dumber in the summer: Our brains can’t stand the heat.
When researchers from Harvard University compared students who had air conditioning and those who did not during a 2016 heatwave in Boston, they found that a lack of AC resulted in 13.4 percent longer reaction times during cognitive tests, and 13.3 percent drop in math scores.
In another study, scientists compared the sales of lottery tickets in St. Louis County — mainly ones that required gamblers to choose between multiple options and simpler tickets with fewer options. When it came to the more complex tickets, sales fell by $594 anytime the temperature went up by one degree Fahrenheit, indicating that the hotter we get, the less we want to think.
The same researchers continued the experiment by asking a separate set of participants to proofread an article, with half of them in a room that was considered cool (67 degrees Fahrenheit), and the other half in a much more balmy 77 degrees. Consistent with past results, the hotter individuals made significantly more mistakes.
Finally, an additional group was asked to decide between cell phone plans in warm and cold rooms, and again, the warmer people were, the shittier the plan they picked, leading the study authors to conclude that “warm temperatures hamper performance on complex tasks.”
As Adrian F. Ward explains in Scientific American, the main reason why summer makes us so stupid is because our brains need more energy for cooling the body down in the heat than to warm it up in the cold. Thus, the brain’s main energy source, glucose, becomes more depleted in summer.
“We use glucose as we walk, talk, breathe and perform other physical functions in our daily lives,” notes Ward, who is an assistant professor in the market department at the University of Texas and has a background in psychology. “We also use glucose when we perform effortful mental functions, such as making decisions, exerting self-control, suppressing emotional responses and even answering math problems. Crucially, glucose — this fundamental source of both physical and mental energy — is a limited resource.”
In fairness, though, the time we can spend drinking cold beers on a hot beach is also limited. So let’s all just dumb things down together and enjoy our himbo brains while we can. Any important decision — or new cell phone plan — can wait until after Labor Day anyway.