Why does sadness make us cry

Some are flat-out ridiculous, like the s view that humans evolved from aquatic apes and tears helped us live in saltwater. Other theories persist despite lack of proof, like the idea popularized by biochemist William Frey in that crying removes toxic substances from the blood that build up during times of stress.

Evidence is mounting in support of some new, more plausible theories. One is that tears trigger social bonding and human connection. While most other animals are born fully formed, humans come into the world vulnerable and physically unequipped to deal with anything on their own. Even though we get physically and emotionally more capable as we mature, grownups never quite age out of the occasional bout of helplessness.

Scientists have also found some evidence that emotional tears are chemically different from the ones people shed while chopping onions—which may help explain why crying sends such a strong emotional signal to others. In addition to the enzymes, lipids, metabolites and electrolytes that make up any tears, emotional tears contain more protein. One hypothesis is that this higher protein content makes emotional tears more viscous, so they stick to the skin more strongly and run down the face more slowly, making them more likely to be seen by others.

Actually being able to cry emotionally, and being able to respond to that, is a very important part of being human. A small study in the journal Science that was widely cited—and widely hyped by the media—suggested that tears from women contained a substance that inhibited the sexual arousal of men.

If you feel unable to ask for help directly, your tears can convey this request without words. This idea is backed up by a small study. Participants looked at pictures of sad and neutral faces with and without tears. In both categories, they indicated that people with tears on their faces seemed to have a greater need for support than those without tears. Think about it this way: How would you respond if you saw someone crying?

Research from also suggests people often seem more agreeable and peaceful than aggressive when they cry. If you walk into an open cabinet door or stub your toe on a sharp corner, the sudden shock of intense pain might bring a few tears to your eyes. Pain severe enough to make you cry does offer one benefit, though. Research suggests that when you cry, your body releases endorphins and oxytocin. These natural chemical messengers help relieve emotional distress along with physical pain.

In other words, crying is a self-soothing behavior. Crying puts you in a vulnerable position. From an evolutionary perspective, this would put you at a disadvantage in a fight-or-flight situation. If you see tears as a sign of weakness, as many people do, you might dislike crying because you want to avoid giving an impression of helplessness.

In fact, expressing your weaknesses could generate sympathy from others and promote social bonding. Researchers believe that crying could reduce the levels of these chemicals in the body, which could, in turn, reduce stress. More research is needed into this area, however, to confirm this. A small study in found that crying can help babies sleep better. Whether crying has the same sleep-enhancing effect on adults is yet to be researched.

However, it follows that the calming, mood-enhancing, and pain-relieving effects of crying above may help a person fall asleep more easily. A study found that lysozyme had such powerful antimicrobial properties that it could even help to reduce risks presented by bioterror agents, such as anthrax. Basal tears, which are released every time a person blinks, help to keep the eyes moist and prevent mucous membranes from drying out.

As the National Eye Institute explains, the lubricating effect of basal tears helps people to see more clearly.

When the membranes dry out, vision can become blurry. Crying in response to emotions such as sadness, joy, or frustration is normal and has a number of health benefits. However, sometimes frequent crying can be a sign of depression. People may be depressed if their crying:. If a person is experiencing symptoms of depression, or someone they know is, then they should talk to a doctor. Crying is a normal human response to a whole range of emotions that has a number of health and social benefits, including pain relief and self-soothing effects.

However, if crying happens frequently, uncontrollably, or for no reason, it could be a sign of depression. What intrigues me about human crying is that as well as crying through obvious triggers like grief, stress, pain etc, we actively seek it out. Then he wept a lot more when I told him how much I was paying.

I used to cry in the mornings before I had to go to school, presumably to try to get a sympathetic response from my family. Then again, I was the headteacher so I never received it. A piece of evidence for this is that people cry when feeling powerful emotions even when alone, when there would be no point in fake-crying to deceive another.

So it is tremendously useful for social bonding — someone who is crying has real feelings to which others can respond. In evolutionary terms this is very useful for group cohesion and trust. Research suggests that when you cry, your body releases endorphins and oxytocin. These natural chemical messengers help relieve emotional distress along with physical pain. In other words, crying is a self-soothing behaviour.

Most answers seem to consider crying as an adult, and note the actually many contexts in which we may do so. Extremes of emotion of any kind as an adult I suspect simply inadvertently trigger the same deeply embedded infant response. While howling makes sense as a signal, all the others — wavering voice, tears, shaking etc — seem more likely simply inadvertent side-effects of presumably the huge wash of hormones humans must need to sustain a long, loud howl that uses a huge amount of energy for an infant.

The infant body is literally throwing the kitchen sink at what, for all it knows, might be a life or death situation. This makes sense as the human body has a wide array of other unhelpful physical side effects to its own hormonal responses — tears etc are just unusually visible ones.