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The Persisting Mysteries of Tears

There are countless folk beliefs about crying, but the science behind shedding tears is still surprisingly blurry.
August 2, 2021, 1:00pm

The propensity to cry emotional tears is uniquely human. Of all the claims to human exceptionality—consciousness, intelligence, innovation—it is the liquid that falls from our eyes when we are sad, happy, jealous, angry, and grateful, more than anything else, that we can call ours, and ours alone.

And yet the act of emotional crying is poorly understood. There is remarkably little consensus about the purpose of crying, its underlying physiology, and its impact on our moods. “What intrigued me about crying is how few people in the world have been studying it,” said Lauren Bylsma, an assistant professor of psychiatry and psychology at the University of Pittsburgh. “You would think with such a ubiquitous and important behavior, there would be more known about it.”

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Myths abound about crying, and they have for hundreds of years. In the 1600s, it was thought that emotions, like love, heated the heart, “which generated water vapor in order to cool itself down. The heart vapor would then rise to the head, condense near the eyes and escape as tears,” Mandy Oaklander wrote in Time Magazine in 2016. At the beginning of the 20th century, it was believed that witches could be easily detected “by the well-known fact that a witch could shed only three tears and those from the left eye."

A persistent analogy for tears has been urine. A Yiddish phrase for crying translates to "pissing from the eyes." American psychoanalyst Phyllis Greenacre proposed that neurotic weeping by women was an exhibitionist form of penis envy. Women could display “shower weeping,” a flood of tears, or “stream weeping,” a gentler trickle. A shower weeper cries “in anger and in partial resignation because she cannot approximate male urination,” Greenacre wrote. “Stream weeping is a substitute for male urination, the penis envy appearing in periodic aggressive demands for the male organ accompanied by fantasies of its possession.”

Why We Sigh

The most universal conviction about crying today isn't penis envy but that crying is good for you—that shedding tears is a kind of “safety valve" to release emotional energy, or actual chemical substances from the body. This idea was seemingly backed with science in the 1980s, with the book Crying: The Mystery of Tears, by biochemist William Frey. Frey proposed that crying expels toxins from the body, and his findings that emotional tears contain different compounds than other kinds of tears are often referenced in popular media when attempting to explain how crying makes you feel better. 

But while even Aristotle wrote that crying “cleanses the mind” of suppressed emotions, it turns out that many of these folk beliefs about tears don't hold up—and not just the more extreme ones about witches or emotional vapors. Today's leading crying researchers say there's no conclusive evidence that the act of shedding emotional tears intrinsically makes you feel better, nor that crying's main function is to excrete toxins.

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“It’s clear to me that it’s become a scientific meme that’s out there in popular culture, and it just won’t go away,” said Randolph Cornelius, a professor of psychological science at Vassar University. 

While the exact physical mechanisms of crying aren't yet agreed upon, some mysteries have begun to be unraveled. For instance, it's likely that who is crying, why they’re crying, and who they're crying around is more important than the contents of the tears themselves. Processing, feeling, and sharing your emotions is a good thing; crying may be less about "peeing from the eyes" and more a powerful social signal to others that we need help.

Charles Darwin viewed tears as a meaningless physiological byproduct. He acknowledged that children cry out vocally, but he thought that tears were a result of contracting the muscles around the eyes. If crying made a person feel better, it wasn't because of the tears; "the writhing of the whole body, the grinding of the teeth, and the uttering of piercing shrieks, all give relief under an agony of pain," Darwin wrote

British anthropologist Ashley Montagu also had a purely physical theory for tears. In 1959, he wrote that when people inhale and exhale during crying, it could dry out the mucous membranes of the nose and throat—crying would protect against this drying. But considering that babies do not cry when they are first born, and we don’t cry during other periods of intense inhaling and exhaling (like exercising), this was ruled out as a likely explanation. Others believed tears existed only for purposes of manipulation. In a 1942 book, UC Berkeley professor of physiological optics Gordon Lynn Walls wrote that weeping “serves no physiological purpose whatsoever. Its value is wholly psychological and economic—as every woman knows!” 


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We know now that tears are produced by the lacrimal gland, whose main job is to keep the eye clean and moist. There are three kinds of tears: basal tears, reflexive tears, and emotional tears. Basal tears moisten and protect the eyes from tiny particles. Reflexive tears are produced at higher volumes when larger particles or other irritants enter the eyes, even bright light. Eating something spicy or throwing up can also produce reflexive tears. Emotional, or psychogenic, tears are produced in the absence of a physical irritant but in response to a wide variety of emotional states. 

Frey, a "self-appointed student of 'psychogenic lacrimation,'" as the New York Times called him, was captivated, as many others before him, by the mystery of emotional tears. “What value are tears shed in agony or in joy?” he wrote in his book. “How can tears help a lost hope? Why don’t humans just express their anguish like other animals by whimpering or crying out?” (Interestingly, Frey wrote that he hadn’t cried since he was 12 years old and worried whether his lack of crying was “healthy and normal.”)

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When comparing emotional tears from 42 women to irritant tears from 61 women, Frey found that the protein concentration of emotional tears was 21% higher. He also found that emotional tears contained more levels of other chemicals: prolactin and adrenocorticotropic hormone (ACTH), stress hormones, and leucine enkephalin, a naturally-occuring painkiller  similar to morphine. 

Ad Vingerhoets, a professor of clinical psychology at Tilburg University in the Netherlands and arguably the world's leading researcher of crying, said that while Frey’s work captivated popular audiences, it hasn’t been verified in the years since—though he has tried. 

“It hasn't been disproven, but it’s also telling that it hasn't been replicated,” Bylsma said.

Vingerhoets said he doesn't consider it logical to think about tears solely as an excretory product. Nearly all our glands excrete hormones, including the salivary ones. Yet, no one suggests that when we drool, it helps us to relax because it reduces the levels of toxic substances in the blood. Additionally, many tears are reabsorbed back into the body; as excretory mechanisms go, tears wouldn't be a very effective one. 

“If it was just about removing toxins, leaking out of your eyes a bit is not going to do anything,” said Marc Baker, a teaching fellow in the department of psychology at the University of Portsmouth in the UK. “The amount of things you could actually remove from the body through tears is so minor.”

Even if there is a difference in the composition of emotional tears, Bylsma suspects it would be a secondary result of the body being in different emotional states. By that, she means that when you emotionally cry, you’re likely to be more activated, stressed, and have higher levels of certain hormones in the body already.

“I’m someone who tries to be extraordinarily fair-minded and open-minded about scientific matters,” Cornelius said. “But one person whose work I disagree with is Bill Frey.”

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It's incredibly hard to get away from the idea that emotional crying is inherently good for you. In an older study from 1986, Cornelius analyzed popular magazine articles spanning 140 years, and found that 94% of them promoted the idea unconditionally. The press often warned that if a person suppressed crying, it would be “deleterious to the body and mind.”

It's true that when researchers ask people if crying makes them feel better, most say yes. But this contradicts controlled studies, which usually find that showing people sad films and making them cry leads to more depressed moods. In Vingerhoets’ book, Why Only Humans Weep: Unravelling the Mysteries of Tears, he wrote that when people in the general public were asked if crying was good for them, 70% said it was. But in the International Study on Adult Crying, a large survey that included people from 37 countries, only half of the respondents felt better after they cried. In 2011, Bylsma studied daily diary entries of female students, finding that only 30% of them felt better after crying, 60% felt the same after shedding tears, and 9% felt worse. 

Do people actually feel better when they’ve cried, or are they only remembering the times that they did? Or did they feel better because of a natural return to baseline emotion that would have happened even if they didn’t cry? It could be that it’s just the passage of time that makes people feel better, not the crying itself. Because crying is so commonly believed to make us feel better, people could be more prone to remember the times that it did improve their moods. 

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“The myth is still that people feel better after crying,” Bylsma said. “There are some mechanisms by which that might be true. But it’s not the case that that always happens.” 

Crying is believed to have evolved from vocal distress and separation calls that other animals perform, said Bylsma. A baby’s crying has been called an “acoustical umbilical cord” and has been proposed to be an attachment behavior to call back caregivers when they're out of sight. 

Evolutionarily speaking, it is beneficial to have a visual signal of distress, not only a noisy, vocal one that could attract unwanted attention, Cornelius said. He thinks that tears evolved to be such a communicative signal at close range to tell others that we are vulnerable and in need of assistance. This is the leading explanation for tears: that they signal to others that we need help, and facilitate bonding and connection with others.

A handful of studies have found that when people look at pictures of faces with tears added or with no tears, people are better able to recognize others' emotions when they have visible tears. They also have feelings of kindness, empathy, and connectedness to people in the teary photos. In general, crying brings about positive reactions from others, Vingerhoets said. When people in a study were told stories in which a main character did and didn’t cry, the participants were more willing to offer emotional support to the criers. 

But any accompanying physiology of crying is still unconfirmed. There are a handful of biological theories as to how crying might physically contribute to make a person feel better- from an increase in parasympathetic nervous system activity, the release of substances like oxytocin, nerve growth factor, or endogenous opioids. It has also been proposed that the rhythmic nature of sobbing, and inhaling cool air, can calm a person down. None of these theories have been definitively pegged as a singular explanation, Vingerhoets said, and it's likely one never will; they act in combination with social signaling and support.

Why you cry, and who you cry around, makes probably the biggest difference as to whether crying feels good, Bylsma said. When people have support from others, or if crying helps them resolve an issue, or understand it better, they are more likely to feel better after. If people are shamed for crying, or embarrassed, then they’ll feel worse. “How do those around you react?” Vingerhoets said. “If they react very positively, try to comfort you, offer their shoulder, and so on, then you feel better. But if you feel ashamed, if others laugh or become mad, you’ll never experience a mood improvement.” 

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A crier’s personality, mood, mental health, and location can also drive the frequency of crying, and whether it's a positive or negative experience. Cross-cultural work has found that people cry more in richer, more democratic, and individualistic countries—highlighting how crying behaviors "relate to freedom of expression rather than to suffering," as the authors noted. People who are extraverted and empathetic are associated with greater tendencies to cry at both positive and negative experiences, and neuroticism is associated with higher crying proneness with only negative triggers. 

Being brought to tears by another person, compared to being responsible for the crying on their own, has been related to worse moods. And how much control you have over a situation can influence whether you feel better after crying or not. The most common emotional trigger for crying, Vingerhoets said, is feeling powerless or hopeless, which is often accompanied with sadness, fear, anger, or disappointment.

These findings don't fully cover all of crying’s mysteries—how some people report feeling better when they cry by themselves, for example, or why studies continue to show that women cry more than men (it could be sociocultural, or have a hormonal influence). Also, in a study from 2011, a double-blind experiment from researchers at the Weizmann Institute of Science in Israel found that men who smelled emotional tears from women, compared to saline placebo tears, reported less attraction to pictures of women—along with a dip in testosterone. 

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Noam Sobel, one of the study’s co-authors, told Time Magazine that while the tears lowered sexual arousal, more significantly, they might have just been reducing aggression via the lowering of testosterone. He said his team was trying to determine the 160-plus molecules in tears to try to understand how exactly a small amount of a subjectively scentless liquid could do that. 

Studying crying is notoriously difficult. Randomizing people to be in different conditions is the gold standard in research to avoid bias or confounding factors—but it’s impossible to randomly assign people to a crying or non-crying group. They have to be sorted later when you learn who cried and who didn’t. 

Frey’s 1985 book is fascinating, if not for its excretory theories then for its insights into the struggles of studying and provoking tears. Getting people to ethically cry reflexive tears is tough. Exposing them to an irritant could cause damage, as Frey noted while eliminating potential substances like ammonia, chemicals used in tear gas, and menthol crystals. 

Frey decided to use an onion to bring on tears, but even that was not as simple as he thought it would be—the onions had only partial success. The team tried horseradish instead, accidentally buying 15 pounds worth of foot-long horseradishes from a Minnesotan market. But the horseradish was too caustic, and the surplus had to be donated to staff who took it home to make horseradish relish. Finally, Frey wrote, they returned to the onion, specifically the U.S. No.1 white onion, freshly grated in a blender, which led most people to produce tears within a minute.

When it came to emotional tears, another challenge was selecting movies that would reliably make people cry. Though Frey thought Sundays and Cybele was a “very sad, emotional movie,” only 10% of people cried while watching it. The winning movies were Brian’s Song, a made-for-TV movie about football players Brian Piccolo and Gale Sayers, and All Mine to Give, a movie about a 12-year-old son of Scottish immigrants finding homes for his siblings after his parents die. 

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Bylsma said that ultimately, the lab is not a naturalistic crying situation, and so she hopes the crying field begins to monitor people’s moods after crying out in the real world, perhaps with wearable technology. 

Other innovations could better help us understand what’s going on in the body when people cry, like capturing people crying with functional thermal infrared imaging (FTII), an approach Baker has developed. The temperature of the face is usually around 85 to 95 degrees (though the nose can be cooler, Baker said, depending on whether people are anxious; noses tend to cool down during anxiety). When people start to cry, Baker's imaging has shown a spike of sympathetic nervous system activity and sweat forming on the upper lip. 

Thermo imaging of a person crying

Courtesy of Marc Baker

“At that point, we start to see the tears, and we see this really quick skin temperature change,” Baker said. “Within 30 seconds, the whole face is getting really hot, just rocketing up in temperature. And it stays that way for about five minutes.” Baker hasn’t yet used thermography to compare different kinds of crying, but he said he suspects there might be variation between reflexive crying and emotional crying.

Thermo imaging of a person crying

Courtesy of Marc Baker

It's just a starting point to getting at what's happening in the body during crying, but Baker said one thing is for sure: “We see huge levels of physiological arousal that seem to be counterintuitive to the idea that it makes you feel better. For the most part, we would consider that not as a release mechanism—you're not returning to baseline or calming down. You're very much accelerating in arousal.” 

A problematic side effect of people believing that crying is unconditionally good for you is that they might be worried if they don't cry very much. It's not that simple. “I don't think we have the power to influence our mood either by suppressing crying or letting it out,” Vingerhoets said. 

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Vingerhoets and his colleagues have studied people who rarely, if ever, cry—sometimes for up to 50 years. He said they didn’t find any large differences in their overall well-being. It can’t be concluded that crying is either cathartic or inherently good for one’s health, Vingerhoets said. But just because crying isn’t pumping out toxins from the body doesn’t mean it doesn't have benefits, or that openly processing your emotions isn’t good for you. It just means that crying isn’t doing the work by itself. 

Criers were found to be more empathic, they felt more connected to others, and they also received more social support from others. And it's an inescapable fact that certain populations are more pressured by society not to cry. Slightly under half of the 475 non-criers were men who said they had learned not to cry. Non-criers were less likely to have seen their dads cry, and thought that a lack of tears was associated with strength. 

In Vingerhoets and his colleagues’ latest study, they’re focusing on how crying people are perceived. They’ve found that when people who cry are seen as having a valid reason to cry, they’re perceived as warm and reliable, the kinds of people that others want as friends, neighbors, or co-workers. “If you are authentically showing your emotions, that has a positive effect on your perception,” Vingerhoets said.

Crying, just as it can operate as a signal of our humanity, can teach you intimate things about yourself. Vingerhoets was surprised to find himself crying at the made-for-TV movie A Child's Wish, about a father who was fired from work for taking time off to care for his daughter with cancer. The daughter requests, through the Make-a-Wish Foundation, to visit the White House, where Bill Clinton (playing himself) tells her that of all the important guests he's welcomed there, she's the one he's most honored to host. “Apparently the topic of this movie, this specific aspect, is something that is very important for me,” Vingerhoets said. 

Outside of garnering social support, crying might force us to think about what’s bothering us. “A lot of time when people are dealing with emotions, one maladaptive strategy is to avoid [them] and not think about them,” Bylsma said. “Crying forces you to think about it. When you cry, you can’t really think about anything else.”

As the philosopher Jerome Neu wrote in his book, A Tear Is an Intellectual Thing, emotional tears continue to be mysteriously connected to our thoughts, personalities, and identities.  "This is not to say they are the product of conscious deliberation and calculation, but it is to say they depend on how we perceive the world, on how we think of it, rather than on how the world simply, in fact, is," he wrote. "They express our nature as well as the nature of the world.”

Follow Shayla Love on Twitter.