Why do we laugh? What's the evolutionary point of it?

 

Ok... let me answer the most basic part first: it's a part of our communications, and therefore quite useful.

Something unexpected happens that is quite harmless (not dangerous) then there's a good chance that we laugh. If that unexpected event links back to something that happened in the past or has otherwise some meaning to the us, it's likely that we'll be roaring with laughter. It's even funnier then.

 

That's a useful communication to explain a rather complicated concept very quickly.

 

But what is the point of just rolling on the floor laughing, almost completely incapacitated by laughter, tears in our eyes and all?

If I try to think of human evolution, I think of a bunch of cavemen. And I cannot imagine a bunch of cavemen having any benefit from laughing. It makes noise. It distracts any guarding cavemen (they also want to know what's so funny, and will consider to leave their posts). It does not produce food. Yes, it creates a group feeling, but other animals don't need laughter to form cohesive groups.

 

The only thing I can come up with is that it's well-known that women like funny men, and men like funny women. Are jokes our peacock-feathers? Pointless for all survival, but awesome for getting laid? Or is there another good reason?

Laughing is indeed, according to some people, a trait of sexual selection.

In addition (or alternatively) laughing is also known to play a role in stress relief, and of course this could give an evolutionary advantage.

 

 

I've also read that there are some theories that laughter was a reaction to play attacks (tickling). This allows children to play roughly while knowing neither are being hurt. This also helps play a role in our social hierarchy, if you are comfortable with someone it's easier to laugh etc. Obviously this is very speculative but it's an interesting perspective.

It would be interesting to know what the proponents of AI have to say about this. There are those who believe that eventually artificial intelligence will become so advanced that it will take the place of humans (i.e we will abandon our frail biological body and live in a strong artificial one, the first step being 'consciousness uploading'). However, laughter is one of the characteristics of being human, and something that an artificial intelligent machine will never do.

 

Laughter is also needed in everyday life to help us relax both within ourselves and in the company of others, so it has an evolutionary advantage in reducing excessive mental or physical pressures (stress, as mentioned above), and consequenlty high blood pressure, heart disease, depression etc. 'Laugther therapy' is pretty established in some countries and it is used against these conditions with some success.

Laughter is also needed in everyday life to help us relax both within ourselves and in the company of others, so it has an evolutionary advantage in reducing excessive mental or physical pressures (stress, as mentioned above), and consequenlty high blood pressure, heart disease, depression etc. 'Laugther therapy' is pretty established in some countries and it is used against these conditions with some success.

While this is obviously true, it does not address why is it necessary to shake your body, and make noise? Why not reduce stress silently?

While this is obviously true, it does not address why is it necessary to shake your body, and make noise? Why not reduce stress silently?

 

It may have to do with the rapid air flow into and out of the lungs during laughter, so it is just a by product of the laughing prosess. Also the noise acts as a feedback loop which enhances the laughter (if you hear laughter you laugh yourself). So it is an integrated process with individual components, some of which are more relevant than others.

Yes, but why exactly like that, and not for example howling at the moon?

See the following for some background info on laughing...

 

http://www.nytimes.com/2007/03/13/science/13tier.html?_r=1&ex=1174536000&en=9e64514e5d308a59&ei=5070&emc=eta1