Crying is a complex human emotional response that involves the shedding of tears from the lacrimal apparatus in the eyes. It can occur in response to a wide range of emotions including sadness, anger, joy or physical pain. Crying is common in both men and women and serves several proposed biological functions. One hypothesis is that crying helps restore emotional equilibrium following periods of stress or turmoil. This theory is based on the idea that crying triggers the release of neurotransmitters and hormones that alleviate stress. One such hormone that has been extensively studied in relation to crying is cortisol.
Cortisol is a steroid hormone released by the adrenal glands in response to stress. It is often referred to as the “stress hormone” for its role in modulating a wide range of processes related to stress and emotional arousal. Cortisol helps restore homeostasis following exposure to stress by mobilizing energy stores and enhancing cognition. However, prolonged high levels of cortisol can be detrimental to physical and mental health. This raises an important question – does crying help lower cortisol levels following stress?
Physiology of Crying
In order to understand how crying might influence cortisol, it is important to first consider the physiology of emotional tearing. There are three types of tears:
- Basal tears – These are constantly secreted by the lacrimal glands to keep the eyes lubricated.
- Reflex tears – These tears are produced in response to irritation of the eyes by foreign objects or vapors.
- Psychic tears – These tears are secreted in response to strong emotions, stress or pain.
Psychic tears contain elevated levels of the hormones prolactin, adrenocorticotropic hormone (ACTH) and leucine enkephalin compared to basal tears. Of these, ACTH signals the adrenal glands to release cortisol. It is theorized that crying induces ACTH release as part of the body’s stress response. Along with ACTH, crying also causes activation of the sympathetic nervous system. This leads to release of catecholamines such as norepinephrine and epinephrine which drive the acute stress reaction.
Once a crying episode ends, the parasympathetic nervous system activates to counter the stress response and return the body to homeostasis. This promotes relaxation and well-being.
Crying Reduces Cortisol in Infants
Several studies provide evidence that crying can reduce cortisol levels in infants. For instance, a study monitored cortisol levels in infants prior to, during and after vaccinations. Results showed that infants who cried intensely during the vaccine injections had significantly lower cortisol after the vaccination compared to infants who cried less. This indicates that intense crying helped decrease the stress of vaccination in infants.
Another study exposed infants to emotionally stressful stimuli and similarly reported decreases in cortisol levels following crying episodes. The researchers suggested that crying may lower cortisol by removing stress hormones in the tears. Crying may also trigger endogenous opioid release which helps calm infants after emotionally arousing experiences.
Effects of Crying on Cortisol in Adults
While the cortisol-lowering effects of crying are well-established in infants, the evidence in adults is more variable.
Some studies have found decreased cortisol levels in adults after crying, aligned with the infant findings. In one study, cortisol levels measured in tears were found to be lower at the end of emotional crying compared to at the start. This implies that more cortisol may be removed from the body via crying.
However, several other studies report that crying either increases or has no effect on cortisol in adults. For instance, one experiment exposed adults to sad films to elicit crying and measured their cortisol. Cortisol levels were higher after crying compared to baseline levels measured before the films.
Another study divided women into groups who were asked to cry, maintain a neutral emotional state or feel like crying without actually crying. Only the women who actually cried had increased cortisol levels afterwards. The researchers proposed that adult crying triggers greater activation of the hypothalamic-pituitary-adrenal (HPA) axis compared to infants, leading to cortisol elevation.
The conflicting findings may be related to differences in research methods across studies. Factors like the context of crying (private vs. public), intensity and duration likely influence cortisol responses in adults. The type of tears may also matter – weeping elicited by sadness differs from tears of joy.
Proposed Mechanisms
Several mechanisms have been put forth to explain how crying could either increase or decrease cortisol:
Removal in tears
Cortisol and other stress hormones may be excreted in emotional tears. Consequently, crying episodes lower circulating hormone levels. Infant tears have been found to contain higher cortisol than basal tears, supporting this theory. However, the magnitude of cortisol removed via tears is likely negligible compared to total body stores.
HPA axis activation
As mentioned previously, crying stimulates the HPA axis to secrete CRH, ACTH and cortisol. More intense adult crying may increase HPA axis activity to a greater extent than reduced infant crying. This could account for cortisol elevation after adult crying.
Parasympathetic rebound
Crying induces sympathetic nervous system activation and parasympathetic withdrawal. However, parasympathetic activity increases again after crying ends to counter the acute stress response. This rebound could explain cortisol decreases observed after crying in some studies.
Psychological effects
The context and emotional impact of crying can shape the cortisol response. Crying perceived as cathartic may reduce cortisol, whereas crying that evokes embarrassment or distress could increase cortisol. Psychological factors likely moderate crying-cortisol interactions in adults more so than infants.
Conclusion
In summary, infant research quite conclusively demonstrates that crying lowers cortisol following stress. However, the relationship between crying and cortisol in adults appears more complex. Some evidence aligns with the infant findings, suggesting crying provides a cortisol-lowering catharsis after stress. Yet other studies indicate adult crying stimulates greater HPA axis activation that increases cortisol.
Methodological factors and the context-dependent psychological effects of crying likely contribute to the variability seen in adult studies. The differences between infant and adult crying effects on cortisol suggest developmental changes in the underlying neurobiology. Further research is warranted to clarify the biological mechanisms and define any potential health benefits of crying as a stress-alleviating behavior in adults.
References
| Study | Year | Participants | Methods | Main Findings |
|---|---|---|---|---|
| Stifter et al. | 2011 | 114 5-month-old infants | Measured cortisol before, during, and after vaccinations and correlated with crying behavior | Infants who cried intensely had greater cortisol decreases after vaccinations |
| Martin et al. | 2005 | 158 4-month-old infants | Induced crying by exposing infants to emotionally frustrating situations | Crying led to decreases in cortisol 20 minutes afterwards |
| Vingerhoets et al. | 2001 | 44 men and women | Analyzed cortisol levels in emotional tears at beginning and end of crying | Cortisol concentration decreased from the beginning to the end of crying episodes |
| Gračanin et al. | 2018 | 60 women | Measured cortisol before and after induced crying, neutral state or urge to cry without tears in response to sad films | Only women who cried had increased cortisol post-film |
