Why cry?

[Horza2002]

I was wondering if anybody knows the reason why we cry when we are upset or in pain?

 

From what I can see, the only benifit that arises is letting other members around you that something is wrong. However, in the process, you are loosing water a salts in the tears themselves?

[Cap'n Refsmmat]

I don't think the minor water loss from crying would be significant enough to be an evolutionary disadvantage. I don't know many people who got critically dehydrated because they watched a sad movie.

 

The social benefit could be quite large, though. When harm comes to you, tears encourage the community to come to your aid, building altruism.

 

I don't know if there's any specific research in this field though.

[Neco Vir]

This may be extremely similar to what Cap'n Refsmmat said...

If you look at it from an evolutionary point of view, it generated sympathy from others and this gave the crier a greater chance of survival.

It is a behavioral thing, the way we view crying as a visual for an emotion, and it has helped humans survive, learn, and understand eachother, even if we have been a bit savage at times in history.

Edited August 5, 2010 by Neco Vir

[CharonY]

Also it would be an oversimplification to attribute everything to specific adaptations (i.e. exclusively in terms of selective advantages or disadvantages). Except in cases of extreme selective pressures other mechanisms are involved in governing the spread of a given trait.

[Ringer]

All animals that live in groups, and many that don't, have different cries or calls (that I'm aware of). Part of what it is thought to be in many animals is an attempt to scare off a would be attacker, in the example of a pained outcry. If I remember right there are striking similarities in most animals cry of pain, anger, excitement, etc. But like Charony said not everything that any animal has is absolutely a survival mechanism and could be explained as such

[PhDwannabe]

Many behaviors or body states which correspond to emotion have plausible theories as to their evolutionary function. Human beings evolved an extremely complex social system, and the development of increasingly complex social networks served as a powerful evolutionary force for our species and its recent ancestors (for instance, most scientists in the area believe that it drove the development of a massive, calorie-sucking neocortex.) During this rapid development, old evolutionary architecture was "co-opted" for new needs. Suppose you're really disappointed in or really disapprove of somebody's behavior--say, they're telling you a happy, unapologetic story about incest they've engaged in. Now, think about the face you'd be making--does it look anything like this? Probably something like it. You might do something similar if I threw up in front of you. This is one of the "Ekman faces" for disgust--part of the landmark study of the universality of facial emotions. But why does this weird arrangement of the facial musculature signify disgust? Because that face has its origins in an evolved response to protect the biologically important/expensive/difficult-to-replace sense organs of the face from noxious environmental stimuli which could do them harm. Put some hand sanitizer on your hands and wave them in front of your cat--you'll get the same expression. Why do hand-sanitizer-irritated cat and human grossed out by vomit make the same face as human outraged by incest story? Because this evolutionary architecture has been co-opted for a social purpose. We needed a way to signify that others' behavior was repulsive before we had the language to say, "Dude, you're totally a noxious environmental stimuli."

 

So, how about crying, then? Crying's a tougher case. The distinct behavior of human emotional crying appears to be just about without precedent in the animal kingdom, although the two parts that comprise it are not novel in our species: the loud vocal wailing, and the lacrimation. Animals at far younger parts of the evolutionary tree than us engage in alarm behavior, including vocalizations. That part is not difficult to understand, evolutionarily--"hey! I need help!" And just about anything with eyes has some way to clear them of debris or irritants. But why on earth do we combine them? If you're upset and need help, aren't you quite possibly in a situation where it might make sense to be able to see what the hell is going on? Well, maybe that's exactly the point.

 

Our species and its ancestors got pretty smart--smart enough to deceive, cheat, and play tricks. We see some deception in other animals (two hilarious examples here), but man, we're really good at it. We're capable of planning all sorts of nefarious things like: "I'll pretend to be upset and need help, then, when he comes over to help me out... bam! sharp stick!" The addition of this other behavior--previously in evolutionary history just used to clear out the eyes and such--could serve to show we mean business. "Look, I'm not trying to mess with you--I can't breathe properly or see straight, so I'm in no shape to pull any funny business."

 

This isn't my theory, it's Oren Hasson's. David Buss--pretty much the most highly regarded evolutionary psychologist of our time--thinks pretty highly of it himself. Since evolutionary psychology necessarily rests on some amount of post-hoc reasoning, and is difficult to test in many of the conventional ways we're familiar with in the social sciences, I might call it a pretty damn good guess.* Without going further into the methods of evo-psych, and spending more ink justifying why this might be a particularly coherent hypothesis, I'll just leave it there.

 

 

Thanks,

DJ

 

 

 

 

*CharonY's point is well-taken:

 

Also it would be an oversimplification to attribute everything to specific adaptations (i.e. exclusively in terms of selective advantages or disadvantages). Except in cases of extreme selective pressures other mechanisms are involved in governing the spread of a given trait.

 

There's plenty of debate between and among evolutionary psychologists and evolutionary biologists about how deep we can go in terms of describing modern behavior with these sorts of evolutionary explainations. His note that there are plenty of pressures which do not take the form of an obvious selective advantage is very true. Suffice it to say that there's disagreement about most of it. Many of these hypotheses end up quite rightly criticized as just-so stories. Anything that we can't pound into controllable experimental frameworks the way we'd like needs to be taken with one more grain of salt than usual. Offered here was simply one reasonably well-thought-out account of a potential explanation for human emotional crying.