hair

[sfsorrow]

hi, does anybody know why (as far as i'm aware),humans are the only species whose head and facial hair grows unabated,for example you never see another primate with long hair it reaches a standard length and stops.

[Peter Pedant]

erm, no, your eyelashes are not 6 ' long which would be true if your question were true.

And neither are your eyebrows - Dennis Healey being an exception. - Chancellor of the sixties and very long eyebrows.

Basically hair goes through a cycles, of three. two of the names are anagen and telogen. Hair grows, falls out and stops. baldies have hair follicles permanently at stop. Telogen effluvium is when the hair falls out all at once. It may occur post partum.

Dogs - dont know much about them. Most dogs have hair loss twice a year, and this is called moulting. Labradors (which i do know a bit about) famously moult continuously.

Er that's just about it.

[CheekyChops]

Yes but I know what sfsorrow means, even if I don't know the answer. If we didn't get a regular haircut, our hair (on our head) would probably reach our knees. You never see a chimpanzee with long hair do you?

As for eyebrows, I agree that some people have longer ones than others - but I never cut mine, how do they know to stop growing when they reach about 8mm, how do they know when they are the correct length?

A dog has longish hair but the hair on its muzzle never grows to the same length as the body hair (except certain breeds) - how does an individual hair know that it shouild stop growing before the hair right next to it?!?

[CheekyChops]

I have always wonderdthe same as sfsorrow. If humans never visited a hairdresser, most of us would end up with hair that reached down to our knees. You never see a chimpanzee with long hair, do you?

Eyebrows have been mentioned, I agree that some people have longer ones than others, but how does the individual eyebrow know that it has reached its required length and doesn't need to grow anymore?

Also, I have a cat which obviously has hair all over his body. How do the hairs on his legs know that they have to grow to say 3mm then stop, when hairs right next to them on his belly can grow much longer?

Basically I would like to know how a hair knows when it has to stop growing?

[CheekyChops]

Oops sorry, don;t know what happened there - I didn't mean to post almost two identical posts in two minutes!

[Pies]

Sounds like a beard growing competition is on the cards any takers?

[NiceCupOfTea]

American indians don't grow facial hair, their head hair grows to the longest recorded human length. (according to my book of amazing facts, anyway)

[Quizmonster]

Click here for a partial answer at least.

[smorodina]

Native Americans do grow facial hair, but the cultural preference of many tribes was to remove it.

[stevie21]

As explained, each individual hair grows for a certain amount of time and then falls out. That's why eyebrows get to a certain length but not longer - the hair falls out before it can get to be too long.

The hair on every part of the body is the same : the only difference is that hair on your head/face grows for longer before falling out.

It's ALWAYS growing and falling out. It doesn't get to a certain length and then just stop growing.

[sfsorrow]

thanks everyone,except peter,alas my question still remains a mystery,why our hair grows to a longer length than any other primate before falling out