Unique to humankind, tears once helped our ancestors survive. Now they draw out our most cherished human qualities - sympathy, compassion, cooperation – and may keep civilization alive. Humans are the only creatures that weep. The shedding of tears during times of joy or emotional distress is not known to occur as a normal function in any other creature. What evolutionary factor may have been responsible for the appearance of weeping in human beings?
The extended dependency period of the human child at once suggests itself. During the early part of that dependency, when the child is helpless and speechless, its principal means of attracting attention to its distress is by crying; but prolonged crying could be damaging, were it not accompanied by tears. Even a short session of tearless crying in a young infant is likely to dry out the mucous membrane of the nose and throat, rendering the child vulnerable to invasion by harmful bacteria and viruses. Fortunately, tears are present under the eyelids, even in the very young. The antiviral and antibacterial action of mucus is the result of lysozyme, an enzyme present in tears. Within 5 to 10 minutes, Lysozyme renders inactive 90 to 95 percent of bacteria with which it comes in contact.
Weeping established itself as a beneficial adaptation in early humans because it counteracted the negative effects of tearless crying on the nasal mucous membranes. Early human infants who cried for prolonged periods of time without benefit of tears would have stood much less chance of surviving than those who cried with tears.Tearless crying in infancy evolved into wet crying, which in turn eventually evolved into the emotional weeping of older humans. The universal capacity in humans to weep indicates the deep-seated biological ability to feel sympathy which elicits weeping. Indeed, at every stage of human history, the outstanding characteristics humans have been called upon to exhibit have been sympathy, compassion, and cooperation. I suggest that the sympathy evoked by weeping originated when early humans began to recognize weeping in the infant as a signal of distress and an appeal for sympathy and succor; as humans evolved, their responses to the weeping child increasingly sensitized them to the emotional behavior of their fellow human. It is therefore probable that weeping has exercised a humanizing effect upon individuals as well as upon the human group as a community.
In our culture, a taboo has been imposed on weeping boys. Quite early in life, the little man learns that if he cries he will lose favor with his parents and the respect of others; hence, when he feels like crying, he represses the desire to do so. In later life, when he might want and need to cry, he often finds himself unable to. Meanwhile, his repressed weeping may be expressed by the body “weeping” through the skin in various rashes and eruptions associated with the respiratory system, i.e., asthma, suppressed immune system, chronic sore throat, gastrointestinal I.B.S., colitis, peptic ulcer, etc.
Events are ordered otherwise in other cultures – for example, among Romance language-speaking peoples—and they appear to be healthier for it. Emotional weeping among both sexes is expected on the occasions appropriate to them. What is considered a mark of weakness – and quite rightly an inhumane trait – is the failure to exhibit the expected emotional response. In some cultures there seems to be a great deal more human warmth than in others, reflecting a more sensitive involvement in humanity. Weeping contributes to the health of the individual and to the community. It tends to deepen involvement in the welfare of others. The very fact that humans possess prominent noses suggests that they were put there for a purpose. What a waste of the nasal membrane’s lachrymal gland and humanity if we fail to weep!