Why do we cry? The science of tears

Shail Bhatt presents why we cry, and the positive impact this could have on our mental health.

Justin Timberlake may want you to cry him a river, but how would that even happen? It is more complicated than initially anticipated, on account of everything being down to emotion itself. If crying was a shop, then there would be different types of tears for different occasions! Emotional tears, which occur due to sadness and melancholy, are different from reflex tears, such as the ones that occur when chopping onions. Even the chemical composition of these types of tears differs; emotional tears contain higher concentrations of hormones, like prolactin and adrenocorticotropic hormone, which indicate high stress levels, for example.

Emotional tears are caused by the cerebellum, the brain region where we process sadness, which induces the lacrimal apparatus (the edge of the eyes that meet the nose) to release tears. In contrast, sensory nerves in the cornea respond to irritation like dust and smoke by triggering the release of reflex tears, which clear away these irritants from the eyes. Lastly, a third type, basal tears, are continuously present in our eyes and work to keep our eyes from drying up.

Regarding emotional tears, the reason for us breaking down and weeping is to arouse empathy in others and show others that we are vulnerable, stimulating human connection. Thus, sobs and tears create compassion and strengthen bonds. Specifically, tears are usually signals that the individual needs care and support, and it has been demonstrated that crying causes a reduction in aggression of the belligerents. While only humans are capable of emotional tears, crying in general arose from the need for a mother to connect with her progeny.

According to Professor Ad Vingerhoets, a psychologist at Tilburg University in The Netherlands and a researcher towards understanding stress and emotion, there are five types of emotional tears that are triggered by different sources: physical pain, attachment-related, compassionate pain, societal pain, and sentimental-based. The exact stimulation of tears usually occurs due to a blend of emotions, although the helplessness we feel is the primary emotion that triggers our tears.

However, everyone is different, and there are many factors that influence how easily someone cries. There often exists a crying threshold which can be influenced by fatigue, diet and hormonal levels; sex is a major component of the latter, and this threshold differs between men and women due to the different hormones present in the body. The amount of exposure to the gravitas of a situation, the perception of emotionally intense situations, and the ability of individuals to control their tears, are also additional factors.

And, while crying can be exhausting both physically and mentally, science suggests that it is more useful than we think. Crying is cathartic, and stimulates the release of oxytocin and endogenous opioids, which improve mood and relaxation. Sobbing and weeping rhythmically also cause inhalation of cooler air, which lightens our mood.

Therefore, the release of emotion to signal to others the need for care is essential in driving relationships between people. Crying reduces emotional stress, helps us deal with sorrow, and allows us to find solace. So tell Justin that you’re happy to cry, although a river may be somewhat excessive.