Did you know?  Michael Trimble, a British professor at the Institute of Neurology in London suggests that crying tears, for emotional reasons, is a trait unique to humans.

In an interview with Scientific American, Timble answers various questions regarding his new book Why Humans Like to Cry.

He states that

“Tears are necessary to keep the eyeball moist, and contain proteins and other substances which maintain the eye healthy and to combat infection. Tearing occurs in many animals in response to irritants which get in the eye, and in some settings tears fall for simple anatomical facts. When an elephant is standing, tears run down the trunk, but when lying down, the flow is impeded and tears may be seen coming from the eyes. It may be that animals that are abused shed tears, from pain, although observations of this are rare.“

But why do humans cry?

Humans cry for many reasons, but crying for emotional reasons and crying in response to aesthetic experiences are unique to us. The former is most associated with loss and bereavement, and the art forms that are most associated with tears are music, literature and poetry. There are very few people who cry looking at paintings, sculptures or lovely buildings. But we also have tears of joy the associated feelings of which last a shorter time than crying in the other circumstances.

If it is the case that only humans cry emotionally, then there must have been a time in human evolution when tears took on an additional meaning to their hitherto biological functions, namely as a signal of distress, and a cipher for suffering.

In his book Trimble suggests that this is connected with the dawning of self-consciousness, with the development of theory of mind.  So, what can we take from knowing all this ?

According to Trimble, tears are a natural response to not only suffering, but also to feeling compassion for someone who is shedding tears. We should not be afraid of our emotions, especially those related to compassion, since our ability to feel empathy and with that to cry tears, is the foundation of a morality and culture which is exclusively human.

 What are your thoughts on the human evolution of crying ? Do you know something we don’t?  Share it with the Humintell Community!

For more information on how shedding tears of emotion was vital for human evolution and the rise of cultures, read this NY Times Op Ed Piece by Trimble