Are you easily brought to tears at ASPCA commercials? Or does it take a bit more to make you well up? Sometimes it sneaks up on you and before you know it... BOOM. You’re full-blown sobbing. Even something as emotionless as cutting an onion or walking on a windy day can cause those magic eye drops to stream down your face. Like all bodily functions, there must be a biological reason for crying. For most tears, it’s an obvious reflex; you get something stuck in your eye, and tears help to wash it away. How about those emotional tears? Famed evolution biologist Charles Darwin understood the emotional advantage of crying, but the actual tears were, according to him, “an incidental result, as purposeless as the secretion of tears from a blow outside the eye.” Now any good scholar of evolution knows that nature does not tend to favor useful function, so there must be reasoning behind the process, but experts are torn on just what this may be.

Biology Behind Tears

There are different classifications of tears. According to Women’s Heath, reflex tears help to protect our body from irritants such as onions or cigarette smoke. In a paper published in the Human Ethology Newsletter, crying in infants is explained from an evolutionary standpoint as being necessary to attract attention from adults to address whatever needs they have. Babies that cry tend to have their needs addressed and therefore will be more likely to survive and pass on the trait.

Automatic Stress Release

Emotional tears are where the mystery begins. They are triggered in the cerebrum, the area of the brain responsible for emotion, and send a message to the endocrine system to release tear-inducing hormones. One of the most reputable studies on tears and crying was done by Dr. William H. Frey. In his book, Crying: The Mystery of Tears, Frey explained that according to his research, emotional crying helped to relieve stress by ridding the body of potentially harmful stress-induced chemicals. “Crying is an exocrine process. That is a process in which a substance comes out of the body. Other exocrine processes, like exhaling, urinating, defecating, and sweating, release toxic substances from the body. There’s every reason to think that crying does the same, releasing chemicals that the body produces in response to stress,” Frey explained to The New York Times.

He even found that the chemical makeup of emotional tears was different from ordinary lubrication tears. In a Los Angeles Times article, Frey describes how among other differences, emotional tears had more proteins, which helped to support his "release of stress" theory. Frey hoped that his study would help to remove the stigma that our society has placed on crying, particularly in men. “We should comfort people without telling them to stop crying," Frey emphasized.

Combination of Emotions

Tom Lutz, author of Crying: The Natural and Cultural History of Tears, does not agree with Frey’s theory that crying is therapeutic. In The Chicago Tribune, Lutz explained his belief that emotional crying is a combination of conflicted emotions, both happy and sad, which together help to make us produce tears. “If crying were therapy, actors who cry on stage every night and twice on Sunday would be the most psychologically healthy people in our culture, and we know that’s not true,” Lutz said. Mary Beth Oliver, a professor at Penn State University agreed with this theory. “Tears aren’t just tears of sadness, they’re tears of searching for the meaning of our fleeting existence," she described to The Chicago Tribune.

Although experts find it hard to agree on a definitive answer behind emotional tears, they do agree that they must serve an important purpose in order to have withstood so many years of natural selection. So next time you try to stifle your tears at the end of Titanic, remember that they are a healthy human reaction, and let yourself have a good cry.


On the Origin of Crying and Tears. Human Ethology Newsletter. 1989.

Frey, WH. Crying: The Mystery of Tears. Minneapolis, Minn: Winston Press. 1985.