Although the phenomenon is well known, and has been called SAD (seasonal affective disorder), researchers have thought that the general malaise was the result of the cold and gloom.
But psychologists at the Brigham Young University say that bad weather on its own doesn’t cause depression or emotional distress—it’s the amount of sunlight that people are exposed to that matters.
“On a rainy day, people assume they’d have more distress. But we didn’t see that. The one thing that was really significant was the amount of time between sunrise and sunset,” said Mark Beecher, one of the researchers.
They arrived at their conclusion after they compared the emotional health profiles of people living in Provo, a city in Utah, to the weather patterns.