Tears

[ferty]

why do people cry tears when emotional?

[Xollob]

From Wikipedia:
Tears brought about by emotions have a different chemical make up than those for lubrication. It has been suggested from their stress hormone content that tears may be a method of expelling excess hormones from the body.

[MargeB]

They use to fart instead, but this just led to mass hilarity.

[MargeB]

Personal opinion...they were used to expel foreign bodies (dust etc) from the eyes. This became exapted as an expression of pain or sorrow, to communicate this to others.

What is homo sapiens? It is a very nurturing creature. We occupy an evolutionary niche were we all need to cooperate. We raise young to adulthood for an incredibly long time, due to birth canal vs head size constraints.

Thus, any adaptation which eases the communication within these empathetic surroundings would have major benefits, even if it means hijacking the original purpose of something like tears.

This is just my opinion, but I think it has a good chance.

[Aschenbach]

Crying and laughing etc are unusual in that they don't serve a bodily function as such. Therefore to understand why we cry requires knowledge of the cerebral processes involved and we are miles away from fully understanding the human brain and its functions.

MargeB I think your theory is really interesting. But human communications operate on a conscious level allowing us to manipulate others whereas crying can be involuntary.

[MargeB]

I see where you're coming from, but I would say much communication is subconscious or involuntary, but language is definitely conscious. Communication and language are not exactly the same thing. I have language, but autistic children and chimpanzees, while maybe having communication, do not have language since they do not have the conscious element, which is tied into 'Theory of Mind'.

Yawning, for example, and shivering, sweating, shaking, going red, etc, all communicate something even though involuntarily.