Researchers tested the hormone levels of three different groups of men and women who were shown a variety of movies (The Bridges of Madison County, The Godfather: Part II, and a documentary on the Amazon rainforest). Watching The Bridges of Madison County caused both men’s and women’s progesterone levels to surge, triggering the urge to cuddle.

I happen to disagree with this amazing piece of research — it’s pretty hard to cuddle when you’re sound asleep.