Crying is an emotional and psychological response. People cry when they feel an overwhelming emotion such as joy, pain, sadness, and stress.
Crying is the act of shedding tears from our eyes. People cry for a lot of reasons, but most commonly people cry because they are sad. Some people also cry when they are happy, calling them happy tears or tears of joy. Some people also seem to cry at every small thing, without rhyme or reason. However, there is a reason.
In addition to these, our eyes tear up when we are in pain, when we are sleepy, when we yawn, etc. In fact, what most people don’t realize is that we are technically crying every second of every day of our life. Scientifically, crying is when the lacrimal gland under the upper eyelid secrets produce a protein-rich, antibacterial liquid. This liquid lubricates our eye every time we blink and also serves to protect our eyes from the dust and other particles. The liquid then drains via the tear duct on the bottom eyelid into the nasal canal, which also the reason our nose drips when we cry.
However, what we know as crying is when the gland produced extra liquid that tends to overflow from our eye and roll down our cheeks. There are three main reasons why the lacrimal gland produced liquid. One is to protect the eye and keep it moist. These are called basal tears. Second is when something, like dust or chemicals form onions, sting and irritate our eyes. The reflex tears then help use flush the irritant out of our eye. The third type of tears is the one that are caused when we are emotional. These are also the ones that are harder to explain.
Scientists are not exactly sure why we cry, but one of the most commonly accepted theories seem to be is that they are related to stress. Tears contain various hormones, including prolactin, adrenocorticotropic hormone and leucine encephalin. These hormones are predominantly produced in the body due to stress. Hence it is believed that the tears are trying to rid the body of the excess hormones. This is also believed to be the reason why you feel calmer after crying. This also works when we are feeling an overwhelmingly emotion, such joy or sadness. Crying helps use bring our body back to equilibrium and recover from the emotions.
Another theory is that crying serves an evolutionary purpose. It is believed to shut down our fight and flight response, making it seem that we are giving up and surrendering. It shows our vulnerability. Hence, if our opponent or predator sees us crying, they may show pity, mercy, or sympathy, which in the olden days may have just saved out lives. Also, showing vulnerability could invoke pity and help gain support and help from a community.
Crying also serves as a form of communication. It is the most basic form of communication available to children, available much before they can speak. Hence, crying is the only that they can show frustration, pain, fear, or even need. We carry this into adulthood. So when words fail us, we cry. We also bond though crying, as it is considered an intimate thing to do. Crying shows vulnerability and we only show vulnerability to people we love and trust.