Tear expert William Frey spent 15 years studying tears, as head of a whole research team. They discovered that emotional tears contain toxic biochemical byproducts, so that weeping removes these toxic substances and relieves emotional stress. This is only true for emotional tears, not crying caused by irritation such as peeling an onion.
Its... hard to imagine what they were doing for 15 years. Must have been a lot of tests. Yeah, that's a great job: getting paid to cry all day. lol, and being able to cry whenever you need to is a great asset for an actor.
The simple act of crying also reduces the body’s manganese level, a mineral which affects mood and is found in up to 30 times greater concentration in tears than in blood serum. They also found that emotional tears contain 24 per cent higher albumin protein concentration than tears caused by eye irritants.8
The researchers concluded that chemicals built up by the body during stress were removed by tears, which actually lowered stress. These include the endorphin leucine-enkephalin, which helps to control pain, and prolactin, a hormone which regulates milk production in mammals.
They found that one of the most important of those compounds which removed tears was adrenocorticotrophic hormone (ACTH), one of the best indicators of stress. Suppressing tears increases stress levels, and contributes to diseases aggravated by stress, such as high blood pressure, heart problems and peptic ulcers.9
There are some good articles about this:
The article is slightly religious, and possibly a bit conceited in that there are statements like, the human brain is the more complex thing in the whole universe, and only humans can cry.
"Emotional tears are a response which only humans have, for only people can weep. All animals that live in air produce tears to lubricate their eyes. But only people possess the marvellous system that causes crying."
-Gregg Levoy, ‘Tears that Speak’, Psychology Today, July–August, 1988, pp. 8, 10.
Well, Mr Gregg Levoy, I think you should have your head examined for suggesting that Animals don't have any feelings. safe to say I will never read Psychology Today, as it is obviously full of bullshit and lies. I happen to have a dog, and if he is made upset enough, he will cry.
Last, but not least, don't forget to buy the book and cry about the price. It's $60 used, $361 new
"If you are interested in the history of tears AND the chemistry of human emotive weeping then this is a must read. You will find this book widely quoted, and it is good to support the author by purchasing this marvelous work."
Hmm, the "History" of Tears? I wasn't aware there WAS a history of Tears. I mean what, are the tears of past generations somehow different? Perhaps there are hidden vials of royal tears for us to find. Maybe when Cleopatra cries, a magic beanstalk comes out the top of the great pyramid. Call me crazy, but somehow I don't think human tears have changed a whole lot throughout history.