Why are we crying?
From Thumbs, Toes, and Tears: And Other Traits That Make Us Human by Chip Walter:
Scientists are compelled to admit they don’t really understand why we cry. They can only agree that we are the only animal that does. Other animals may whimper, moan, and howl, but none cries tears of emotion, not even our closest primate relatives. And unlike laughing or even speech, there doesn’t seem to be any obvious analog in the primate world. Apes do have tear ducts, and so do other mammals, but they are there purely for housecleaning: Tears bathe and heal the eyes. We have similar plumbing in place to keep our eyes clean and disease-free, but for some reason, at some point in our evolution, a savanna ape, or perhaps an early version of our own species, developed a direct, physical connection between the gland that makes our tears and the emotional parts of our brains. That is unique in nature.
good thing it was tear ducts rather than salivary glands, amirite?
I’m interested in what ingredients are required before crying is triggered (though obviously we all have a different threshold and it changes day to day). Some dramatic movies won’t make me cry even after more than an hour with the characters. This Thai life insurance company has apparently figured out the formula and only needs a few minutes.