WASHINGTON - Crying is known to be a symptom of physical pain or stress but it can improve personal relationships, says a new study.

New analysis by Tel Aviv University (TAU) zoologist and evolutionary biologist Oren Hasson shows that while tears signal distress, they also function as an evolution-based mechanism to bring people closer.

“Crying is a highly evolved behaviour,” explains Hasson.

“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.

“My analysis suggests that by blurring vision, tears lower defences 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,” he reports.

Hasson investigated the use of tears in various 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, according to a TAU release.

“This is strictly human,” reasons 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,” he says.

“Of course,” Hasson adds, “the efficacy of this evolutionary behaviour always depends on who you’re with when you cry those buckets of tears, and it probably won’t be effective in places, like at work, when emotions should be hidden.”

The study was published recently in Evolutionary Psychology.