crying begins at birth and its prime purpose is to stimulate loving and protective feelings in adult. crying is a way for the baby to get what it wants and as adults, this behaviour is perpetuated by some women.
Most women can identify seven different meanings behind a baby's cry to evaluate its needs. women's tear glands are more active than mens's, which is consistent to with greater emotional responses of the female brain.
Men are rarely seen crying in public because from an evolutionary perspective, a man showing emotions, especially around other men, would be put at risk. He'd look weak and this would encourage others to attack him.
for women to show emotions to others, however particularly other women is seen as a sign of trust because the cryer becomes the the baby and is putting her friend into the role of protective parent.
Crying has three known purposes:
1.As an eyewash.
Many zoologists believe this function is relic from an aquatic era when we lived mainly in the water and evolved webbed fingers, webbed toes and down-facing nostrils to allow effective swimming. the tear gland secretes liquid into the eye and the tear ducts act as a drain to remove it via the nasal cavity. crying serves to remove salt and other impurities from the eye- a specialty not seen in other primates. tears also contain an enzyme called lysozyme that kills bacteria and prevents eyes infections.
2. As a stress reducer
Chemical analysis of tears reveals that stress tears, those that roll down the cheek, contain different proteins from those used for eye cleansing. the body appears to use this function to clear stress toxins from the body. this could explain why women say they feel better after 'a good cry', even when where there appears to be no real reason for crying. tears also contain endorphins, one of the body's natural painkillers, which act as a damper to emotional pain.
3. As an emotional signal
Seals and sea otters cry when emotionally distressed because they have lost theri young. humans are the only land animal that cries from both emotions and manipulate emotionally. tears act as a visual signal asking others to hug and comfort the weeper and they encourage production of the hormone oxytocin, the hormone that makes a person desire t be touched and cuddled by another person.