25 August 2009
The evolutionary benefits of crying
by Kate Melville
Crying is known to be a symptom of pain or stress, but an evolutionary biologist from Tel Aviv University (TAU) suggests that tears are also an evolution-based mechanism to bring people closer together and make interpersonal relationships stronger.
"Crying is a highly evolved behavior," explains Dr. Oren Hasson of TAU's Department of Zoology. "Tears give clues and reliable information about submission, needs and social attachments between one another. My research is trying to answer what the evolutionary reasons are for having emotional tears."
Hasson's analysis suggests that by blurring vision, tears lower defenses and reliably function as signals of submission, a cry for help, and even in a mutual display of attachment and as a group display of cohesion.
Published in Evolutionary Psychology, Hasson's research investigates the different kinds of tears we shed - tears of joy, sadness and grief - as well as the authenticity or sincerity of the tears. Crying, Hasson says, has unique benefits among friends and others in our various communities.
Using the deductive tools of an evolutionary biologist, Hasson investigated the use of tears in a variety of emotional and social circumstances. Tears are used to elicit mercy from an antagonistic enemy, he claims. They are also useful in eliciting the sympathy - and perhaps more importantly the strategic assistance - of people who were not part of the enemy group.
"This is strictly human," said Hasson. "Emotional tears also signal appeasement, a need for attachment in times of grief, and a validation of emotions among family, friends and members of a group."
Crying also enhances attachments and friendships, he adds, but taboos are still there in certain cases. In some cultures, societies or circumstances, the expression of emotions is received as a weakness and the production of tears is suppressed. For example, it is rarely acceptable to cry in front of your boss at work.
But multiple studies across cultures show that crying helps us bond with our families, loved ones and allies. By blurring vision, Hasson says, tears reliably signal your vulnerability and that you love someone, a good evolutionary strategy to emotionally bind people closer to you.
Source: Evolutionary Psychology