Michael Trimble, a behavioral neurologist with the unusual distinction of being one of the world’s leading experts on crying, was about to be interviewed on a BBC radio show when an assistant asked him a strange question: How come some people don’t cry at all?
The staffer went on to explain that a colleague of hers insisted he never cries. She’d even taken him to see Les Misérables, certain it would jerk a tear or two, but his eyes stayed dry. Trimble was stumped.
He and the handful of other scientists who study human crying tend to focus their research on wet eyes, not dry ones, so before the broadcast began, he set up an email address—firstname.lastname@example.org—and on the air asked listeners who never cry to contact him. Within a few hours, Trimble had received hundreds of messages.
“We don’t know anything about people who don’t cry,” Trimble says now. In fact, there’s also a lot scientists don’t know—or can’t agree on—about people who do cry. Charles Darwin once declared emotional tears “purposeless,” and nearly 150 years later, emotional crying remains one of the human body’s more confounding mysteries.
Though some other species shed tears reflexively as a result of pain or irritation, humans are the only creatures whose tears can be triggered by their feelings. In babies, tears have the obvious and crucial role of soliciting attention and care from adults. But what about in grownups? That’s less clear. It’s obvious that strong emotions trigger them, but why? Read more