Commusings: Why Humans Cry

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Dear Commune Community,

The topic I explore in today’s essay is a real tear-jerker: Why do humans cry?

I was propelled into this inquiry by my recent trip to Florida. I visited the Sunshine State for 8 eight days – and, for one reason or another, I found myself whimpering every single day. And I’m not a famous blubberer. You may recall that I released a Commune course on Stoicism.

The interesting part of my sobfest was that each bawling session was motivated by totally different emotions and situations. Now, I will say that I was exhausted for much of the trip – so I was emotionally rawer than usual – but, still, the sources of my tears were as varied as snowflakes (or, I suppose, as grains of sand, given my location).

After years, I buried the proverbial hatchet with an old friend. I had a long and public conversation with Dr. Zach Bush about dying well. I watched a grainy home movie of old college friends getting married. The election happened – oh that. And I went to a ceremonial dinner for my aging father at which people gave a variety of laudatory toasts in his honor. 

The provenance of my tears was equal parts happiness, wistfulness, nostalgia, and pride.

Tears are fascinating in this respect —they show up when we’re sad, when we’re overwhelmed with joy, and sometimes even when we’ve pushed our bodies to their limits. But what’s really going on in our bodies and brains when we cry? Are all tears the same? And why do humans cry at all? Is there a deeper evolutionary purpose to this watery expression?

Crying starts in the lacrimal glands, which are almond-shaped structures just above your eyes. These glands constantly produce tears even when you’re not crying to keep your eyes lubricated and protected.  

But when emotions run high, the lacrimal glands get a signal from the brain to step up production. Eventually, the tears overflow the carrying capacity of the eyes and run down your cheeks. 

You can understand this phenomenon as an adaptive process to regulate the nervous system. In other words, crying may be one way the body fosters emotional homeostasis. Let me explain this with some science and then a simple analogy.

When you're experiencing intense emotions—like grief, frustration, or even overwhelming joy—the amygdala activates the hypothalamus, which in turn engages the sympathetic nervous system. This triggers the release of stress hormones such as cortisol and adrenaline. These hormones prepare your body to deal with emotional or physical challenges and heighten your alertness.
 
At this stage, you may notice an increase in heart and respiratory rate and a sense of tension or emotional overwhelm. This stress response is your body’s way of signaling, “Something important is happening—pay attention!” 

This flood of intense emotions may trigger the act of crying. Why?

The body is engineered for homeostasis in countless ways – from temperature balance to pH regulation, from blood glucose management to hormonal crests and troughs. Crying may be another mechanism for instantiating balance. 

Crying is closely tied to the prefrontal cortex—the part of the brain responsible for higher-order thinking, self-awareness, and social behavior.  

When the prefrontal cortex interprets an emotional trigger, it works with the amygdala and hypothalamus to create the physical response of crying. This involves activating areas like the brainstem, which regulates basic bodily functions like breathing.  

When you cry, have you ever noticed your breathing changes? That’s because crying often involves deep, irregular breaths that stimulate the vagus nerve, which calms the body. Crying is the physical manifestation of your nervous system resetting itself.

Once the tears start flowing, the parasympathetic nervous system (PNS) is activated, which helps calm your body down. This is the “rest and digest” part of the nervous system, which counterbalances the stress response. When the parasympathetic wrests control over the nervous system, your heart rate slows down and breathing becomes deeper and more regular. Your body begins to relax.

This explains why people often feel a sense of relief or catharsis after crying—your body is shifting from a heightened emotional state to a calmer, more regulated one.

Here’s the analogy. Think of crying like a thunderstorm. The sympathetic system along with its stress hormones is the buildup—the dark clouds and lightning. And the parasympathetic system and its accompanying relaxation is the rain—the release that clears the tension and brings calm.

Here’s where it gets even more fascinating: not all tears are the same. There are three primary types.

First, there are basal tears. They are omnipresent and fulfill the job of keeping your eyes moist. 

Then there are reflex tears that serve to flush out irritants. These come in handy when you chop onions.

And then there are emotional tears, which are chemically distinct from the more perfunctory tears. 

Studies show that emotional tears contain higher levels of hormones like prolactin, adrenocorticotropic hormone (ACTH), and leucine enkephalin, a natural painkiller. This suggests that crying may chemically help your body release excess stress.

And yes, emotional tears are literally saltier. They have a higher concentration of electrolytes compared to reflex or basal tears. But tears aren’t just salty water. They’re a cocktail of biological compounds designed to protect and regulate your body. 

In addition to water and salts like sodium and potassium, tears also contain lysozymes, enzymes that help protect your eyes from bacteria.

And, emotional tears, as I mentioned, have higher concentrations of prolactin, a protein also involved in lactation.

But what’s really intriguing is the presence of stress hormones like ACTH in emotional tears. It’s as if the body is literally flushing our built-up emotional tension with every tear. Crying is like a release valve.

So, is crying unique to humans? Do animals cry?  

Physiologically, many animals produce tears to protect their eyes. For example, turtles secrete tears to excrete excess salt, and dogs might have watery eyes when they’re sick or irritated.  

But when it comes to emotional crying, humans seem to be alone with their tears. Elephants are often said to cry when mourning, but scientists believe their tears are more reflexive than emotional.  

So why us? Why did humans evolve the ability to cry from emotion? Nature rarely makes a design mistake. Why is crying adaptive? Well, humans need to metabolize stress and trauma and we don’t often do it in the ways other animals do. For example, dogs, cats, opossums, ducks, and horses shake to release stress. Shaking helps release pent-up energy and recalibrate the nervous system.

Prey animals often run or move immediately after a stress-inducing event, even if the threat has passed. For example, a gazelle that narrowly escapes a predator may continue running for a while, even after reaching safety. Physical movement burns off the adrenaline and energy produced during the fight-or-flight response, preventing it from becoming trapped in the body.

Many animals use vocalizations like barking, growling, or howling to release stress and signal their emotional state to others. Wolves, for example, may howl together after a stressful event to re-establish social bonds and calm the group.

Animals like cats, primates, and birds engage in self-grooming or mutual grooming after stress. A cat might meticulously groom itself after being startled by a loud noise. Grooming helps reduce stress by activating the parasympathetic nervous system and providing comfort.

Many animals, particularly social species, engage in play behaviors after a stressful experience. Dogs may initiate playful behaviors like bowing or chasing after an unsettling encounter with another dog. Like shaking and howling, play helps to dissipate built-up energy, relieve tension, and restore positive social dynamics.

Humans don’t regularly engage in any of these activities after a traumatic experience. We’re more likely to experience dorsal vagal shutdown, becoming numb and disassociating with our emotions. This can lead to housing trauma physically in the body. Crying – from the tears themselves to the breathing – is a useful human behavior for releasing tension. 

Then there are our complex social structures. Crying is a powerful non-verbal signal that communicates vulnerability, need, or sincerity. For example, a baby’s cry compels caregivers to respond, ensuring its survival.

As adults, emotional tears can elicit empathy from others, strengthening social bonds. Think about the last time you cried in front of someone—did they comfort you? Crying isn’t just about releasing your own emotions; it’s also a way of connecting with others. Tears are hard to fake. When someone cries, it’s often interpreted as a genuine expression of emotion, which can build trust and deepen relationships.

After delving into the nature of crying, my takeaway is that humans may benefit from crying more. Of course, this is difficult in some cultures that view crying as a sign of weakness. 

But, again, ask yourself … Why would humans cry if it wasn’t evolutionarily adaptive? Crying isn’t just an emotional response—it’s a biological reset button, a social glue, and a stress reliever.  

Whether you’re crying from heartbreak, joy, or sheer exhaustion, remember your tears are doing important work. They are not a sign of weakness, they are a sign of being uniquely and beautifully human.

Here at [email protected] and waxing and waning on IG @jeffkrasno.

In love, include me,
Jeff

P.S. I suppose you could consider crying a GOOD STRESS protocol. It’s hard to be vulnerable. But like fasting, cold water therapy, and other adversity mimetics, crying enhances your ability to return to “center.” I talk all about this in my new book GOOD STRESS, coming out in early 2025. Pre-order now and receive early access to Chapters 1 and 2 — text and audio. And … receive $900 in Commune course bonuses featuring Schuyler Grant, Dr. Mark Hyman, and Dr. Casey Means, among others.