Israeli neurobiologists have discovered that “merely sniffing negative-emotion-related odorless tears obtained from women donors, induced reductions in sexual appeal attributed by men to pictures of women’s faces.” Dr. Noam Sobel, a professor of neurobiology at the Weizmann Institute in Israel suggests that tears are a chemical form of language, saying, “basically what we’ve found is the chemo-signaling word for ‘no’ — or at least ‘not now.’ ” http://www.sciencemag.org/content/early/2011/01/05/science.1198331
That tears serve a biochemical communication function doesn’t particularly surprise me, but I think their evolutionary role is vastly broader than merely suppressing sexual arousal in men. Psychic tears can also be socially adaptively helpful in a wider array of situations – at work or home — by communicating submission. Tom Lutz, a University of Iowa professor and author of Crying: A Natural and Cultural History of Tears, describes such crying as “the human equivalent of a dog putting its tail between its legs – please, we can say with tears, I am already abased, do me no further harm.”
We know that psychic or emotional tears, because they are exceptional, force us and those around us to acknowledge that something important has just happened – my boyfriend proposed to me, my boss yelled at me, I was deeply moved by a sense of the divine, my dog died – and that we should pause and take a moment for reflection.