Why Humans Cry
Crying is one of the most fundamental and mysterious of human expressions. It is a universal phenomenon, transcending culture, yet it is often deeply personal and, in many societies, actively discouraged. While functionally, tears are necessary to protect the eye, emotional crying is a far more complex behavior. Currently, humans are the only species known to produce emotional tears. To understand it is to look at a sophisticated interplay of biology, social signaling, and psychology.
More Than Salt Water
At the most basic level, emotional crying is a physiological event. There are three distinct types of tears: basal (which constantly keep the cornea nourished), reflex (which flush out irritants), and emotional. It is this third category that holds the most interest.
Scientific analysis reveals that emotional tears have a different chemical composition than the other two types. They are not simply saline. In a well-known study by biochemist William Frey in the 1980s, emotional tears were found to contain significantly more protein—by some measures up to 24% more—than reflex tears. This protein content includes stress hormones like prolactin and adrenocorticotropic hormone (ACTH), as well as the endogenous opioid leucine enkephalin, a natural painkiller.
This composition points to a primary function of crying: self-regulation. The act of weeping serves as a release valve for an over-stimulated nervous system. By expelling these stress-related chemicals, the body is literally purging the biochemical byproducts of distress. This process helps to restore homeostasis, or internal balance, which explains the sense of calm or relief that often follows a cathartic cry. It is not merely a psychological perception; it is a tangible biochemical reset.
The Language That Binds Us
Beyond its internal regulatory function, crying is a powerful tool for social communication. From an evolutionary perspective, an infant’s cry is a critical survival mechanism—an unambiguous signal of distress that elicits a caregiving response. This function does not disappear in adulthood.
Tears serve as a potent, non-verbal signal of vulnerability, visibly lowering the defenses of observers and often inhibiting aggression. This social signaling is so powerful that its expression is frequently modulated by cultural norms, particularly around gender. Landmark research by Dr. Ad Vingerhoets, a leading world expert on crying, found that on average, women cry 30 to 64 times a year, whereas men cry only 6 to 17 times. This disparity is less a reflection of biological imperative and more one of social conditioning, where expressions of vulnerability have been historically discouraged in men.
Regardless of frequency, the signal remains effective. Studies have shown that observers tend to feel more empathy and a greater willingness to provide support to a person who is crying, reinforcing the communal ties essential for human well-being.
When the Body Speaks
While crying regulates the body and signals to others, its most profound purpose may be as a signal to oneself. Tears are an indicator that an internal threshold has been crossed. They arise when an individual makes contact with an experience so significant it overwhelms their typical emotional processing.
This experience is not limited to negative feelings. While a German study in the early 2000s identified key triggers like loss (death of a loved one) and relationship conflicts, it also found that a significant portion of crying episodes were triggered by positive events, such as weddings, reunions, or moving encounters with art and music. Tears are a marker of meaning. They signify that a core value, a deep attachment, or a sensitive part of the psyche has been touched.
In a clinical context, this can be a pivotal moment. An individual might be discussing a seemingly minor professional setback when they begin to cry, much to their own surprise. The tears are rarely about the surface-level event. They are often the physical manifestation of a deeper narrative—a fear of inadequacy or a profound sense of loneliness. They are the body’s way of bringing this buried information to the forefront of consciousness.
It’s a remarkably common occurrence in my practice. A client will be in the middle of a profound insight, their eyes will well up with tears, and almost immediately, the words tumble out: "I'm sorry." My response is never just to reassure them. Instead, I get curious. I’ll gently ask, "What are you apologizing for?" More often than not, the question is met with a moment of stunned silence. They have no ready answer. The apology is a deeply ingrained, unconscious reflex—a script handed to them years ago that dictates tears are a transgression in need of an apology.
That moment of silence is the beginning of questioning the script. The suppression of tears, a common practice, is an attempt to manage this powerful signal. It is often a learned adaptation from environments where vulnerability was perceived as dangerous. While this control can be a useful skill, chronic suppression can lead to a disconnect from one's own emotional landscape, preventing the resolution of the very issues the tears are trying to reveal.
