I remember teaching a high school English class on Friday afternoon. Since it was Friday, they were allowed to pick and analyze songs on the Internet. One girl selected a tearjerker entitled “Why Tears Fall.” At the end of this discussion, one of the boys piped up, “I know why tears fall — gravity!”
Although that might be a typical male viewpoint, it’s actually much more complicated than that. No one really knows why we cry, and some people don’t cry at all. The most obvious reason would be that tears lubricate the eyes, but that doesn’t explain purely emotional crying. Charles Darwin thought emotional tears were “purposeless”, but that’s not the case today. Theories have been advanced since around 1500 B.C. The Old Testament describes tears as the by-product of when the heart’s flesh weakened and turned to water. A 17th century theory was that emotions heated the heart, which generated water vapor to cool down.
Will we ever know? You might be surprised to learn how many people are studying crying full-time.
A good article with statistics on why we cry is in the March 7, 2016 issue of Time magazine. An abbreviated version is at Time’s website at http://time.com/4254089/science-crying/?xid=newsletter-brief