science of us

It’s Not Your Fault If You Can’t Get Anything Done in the Summer

Photo: Paula Winkler/Getty Images/fStop

I can’t get anything done in the summer, which I’d long assumed was due to my body’s preference for the school-year calendar of September to May. Though I haven’t been in school for many years, I figured there was some lasting psychological impact which made my brain give up every June. Come September, though, I felt ready to start fresh (so much so that I treat it, more than January, as my New Year): reenergized about projects that have stalled, newly motivated, and just … smarter. Today, I am thrilled to announce that I was right — if not exactly for the reasons I thought. I really am dumber in the summer, and, I’m sorry to say, so are you.

A new study found that students who lived in air-conditioned buildings (where the temperature averaged 71 degrees) performed better on tests than students living in buildings without AC (which averaged almost 80 degrees). The tests were administered during a heat wave in Boston, and assessed students’ ability to perform basic addition and subtraction, and evaluated their cognitive speed and memory. Students were sent the tests on their phones twice a day, and took them online, from home. Those in the non-air-conditioned buildings scored lower than their counterparts, but they also answered their questions more slowly — researchers told NPR they found a “10 percent reduction in the number of correct responses per minute” among those without AC.

This finding is particularly relevant (and terrifying) given our warming planet, and the corresponding increase in heat waves. One of the study’s authors, Joe Allen, co-director of the Center for Climate, Health and the Global Environment at Harvard University, told NPR, “There’s evidence that our brains are susceptible to temperature abnormalities.” Their study, too, reflected a relatively small difference in temperature, with less than nine degrees between test groups. Their research didn’t assess whether one’s cognitive abilities decline in direct proportion to the increasing temperature, but it makes me wonder whether conditions might be even worse when it’s 90 degrees, or 110 degrees, as it was in California last week. Just something else to look forward to about the end of the world!

Your Brain Really Does Get Slower in the Summer