The Biological Reason for Tears

I was thinking about this the other day. Why do humans cry? There always seems to be a biological explanation for any type of odd human behaviour, so why the crying? What purpose does it really solve? I can understand things like yawning when you’re tired because it stretches your muscles and brings you more oxygen – or something along those lines, though there doesn’t seem to be any conclusive answer on why yawning is contagious. But why is it that when you’re sad, you begin to leak moisture from your eyes, your throat gets tight, and you begin to sniffle like a toddler?

To relieve my curiosity, I did what any normalĀ  person would do – I googled it. According to the information god that is Wikipedia, there are several theories. We may cry to elicit helping behaviour from others, simply as a reflex to pain, or perhaps as a way of relieving stress and removing toxins (by eliminating hormones related to stress – don’t ask me about the details). From an evolutionary point of view, we may cry because (as states Wikipedia) our blurred vision may impair aggressive or defensive actions and elicit sympathy from an attacker. This one seems implausible to me. “I’m being attacked!” says the caveman, and bursts into tears so that he can do absolutely nothing about it. Hm. According to another article I read, tears indicate to somebody physically close to you that you are vulnerable, while not alerting enemies far away to that fact. That seems a little more reasonable to me – but still kind of silly. I also learned some other interesting things, such as that on averageĀ  men apparently cry once a month, while women cry five times a month. That sounds pretty accurate.

So why do I think we cry? Personally, I think it’s another one of the many inconvenient tricks Mother Nature decided to play on us. I can’t think of anything good crying does for a person, other than leave them with a beautiful splotchy red face. It reminds me of how Mother Nature also thought periods with a side of cramps would be a good idea.