From babies who cry to draw attention of their parents – to tears of athletes after winning major medals, all people cry. Crying is only specific to humans, but people know very little about tears.
Although many animals show tears, tears caused by emotions is specific only to humans. ” The role of tears is to keep our eyes moist. They contain proteins and other substances that maintain ocular health and combat infections,” said Michael Trimble, author of Why Humans Like to Cry. “We cry because of many causes, but we are motivated by emotions and tears are caused by aesthetic experiences unique to humans,” he adds. However, what are tears and what makes us cry?
There are several types of tears:
Tears are not identical, and they differ by the reason that causes them, even the chemical composition is not the same. Basal tears are present all the time and are designed to lubricate the eyes, to nourish and protect the eyeball. The second type, are known as reflex tears, they are formed to protect our eyes from irritants such as wind, smoke, or onions. Finally, the third type is the ones that appear after an argument, or after an impressive film for example. The tears we shed in these situations are called emotional tears, and it contains more protein than the other two types, however, a full research is currently incomplete.
Scientists do not know exactly why we cry:
However theories are numerous. An alternative is that crying occurred during evolution, to signal cases where people were in danger, without making too much noise. “We can imagine that, at one time tears were needed to develop a silent warning system to escape predators,” says psychologist Randy Cornelius.
Later, tears came to fulfill other roles, says Lauren Bylsma, who conducted several studies on crying, “Tears are a way to attract the support of others in situations where we need it,” she says. Babies cry to attract the attention of parents, while adults cry to get the sympathy of others. By crying we can solve our conflicts more quickly. “It’s hard to keep arguing or punishing a person who cries. This is a signal that tells us to retreat”, say researchers at the Belfast University.
The chemical composition of tears is similar to that of saliva:
Among other components, the tears containing proteins, hormones and salts.
A survey estimated that women cry on average 5.3 times per month while men cry only 1.4 times. Another study says that women cry up to five times per month, while men cry only once. A research conducted by Germans scientists show that, on average, women cry for six minutes, while men cry for about two minutes.
The difference between the sexes, from this point of view, may be determined by the culture:
The difference between men and women in terms of crying seems to vary depending on the characteristics of people living in the involved countries. Surprisingly, in Western culture, where is promoted freedom and equal treatment of women, they still cry more than those grown in traditional culture. The differences between how men from different cultures cry is not substantial says Lauren Bylsma. So biologically, women seem prone to cry more and more often.
Tears are generated by the lacrimal glands:
They are located in the upper outer orbit, in the lacrimal fossa sac. Channels under the upper eyelid glands open in the corner of the eye. When tears are produced in excess, these small channels are draining into the nasal cavity, and when their volume is too high, they reach the eye.
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