Why doesn't the rug match the drapes?

May 14, 2009 10:36 AM

Why do some people's hair on their head and pubic hair not match in color?

First off, I'm excluding people who have their hair colored. I know why their hair doesn't match.

I've known women who had dirty blond hair and had black pubic hair. Others I've spoken to have shared the same thing. Given that hair should be the same all over, why is pubic hair sometimes a different color than the rest of your hair?

posted by reenum to health & fitness (30 answers total)

Sun.
posted by applemeat at 10:41 AM on May 14, 2009

It's different hair.
posted by kuujjuarapik at 10:42 AM on May 14, 2009 [4 favorites]

See wikipedia for Androgenic hair.
posted by kuujjuarapik at 10:44 AM on May 14, 2009 [1 favorite]

The genes that determine the characteristics of pubic and other bodily hair are different from those that determine the hair on your head. That's why they grow to different lengths, have different textures, and different colors. I would assume that these genes aren't linked, i.e. dependent on each other, although my grasp of genetics isn't what it once was. But I also think that black and coarse pubic hair is just the typical gene expression for that type of hair, whereas the gene expression for head hair can take a number of common forms.
posted by emilyd22222 at 10:47 AM on May 14, 2009 [4 favorites]

It's not just pubic hair, sun or different types of hair. I have three colors in my beard alone: blond, red, and dark brown. It's weird.
posted by milarepa at 10:47 AM on May 14, 2009 [6 favorites]

I don't know why it's a "given" that hair should be the same all over. And sun isn't the answer either - I know loads of natural blondes with black eyebrows, which should get more or less the same amount of sun. I've got dark brown hair, but the little hair on my arms (for instance) is very light - clearer than blond. For that matter, if hair's all supposed to be the same, why can I grow the hair on my head two feet long, but my eyelashes stay the same? Why are individual hairs in some places thicker than in others?
posted by Dee Xtrovert at 10:48 AM on May 14, 2009 [2 favorites]

Given that hair should be the same all over

That's an incorrect assumption. It's true that all of our cells carry the same genes, but there are all sorts of developmental and environmental factors that alter how each cell acts. For example, skin cells on your callused feet are exhibiting different characteristics than cells on more sensitive areas, like your face. For more dramatic examples, consider that the cells of your liver, pancreas, skin, and biceps all carry the same genetic code.

As another anecdotal example, my beard doesn't match the hair on my head - it's got red and blonde mixed in with the dark brown found on my scalp.
posted by chrisamiller at 10:53 AM on May 14, 2009

I can't even get my beard to match the hair on my head. I have lightish-brown hair and when I first grew a beard it was so jet-black that some people thought it was a fake beard, or that I colored it.
posted by mikepop at 10:54 AM on May 14, 2009 [1 favorite]

Yeah, everyone is right.

i would go ahead and say *most* blonde haired people in the US have darker hair on their eyebrows and other places. Only the really purely Scandanavian and Germanic types seem to be blonde all over.
posted by drjimmy11 at 10:55 AM on May 14, 2009

completely right because I cant think of a single person I've known who ever did have matching hair all over their bodies. men usually have very different beard color than hair color.

I am a northern european pasty blonde type and my hairs are quite various different colors...
posted by supermedusa at 11:03 AM on May 14, 2009

A possibility in some cases will be that the particular woman in question is a chimera.

Also, I'm a guy and I have the same beard-mismatch effect as mikepop mentions. (And I don't think it's because I'm a chimera, in my case.)
posted by XMLicious at 11:03 AM on May 14, 2009

Only the really purely Scandanavian and Germanic types seem to be blonde all over.

I'm fairly purely Scandanavian, but I have much darker pubic hair then any other hair on my body. I never thought about it, but it is kinda weird.
posted by InsanePenguin at 11:05 AM on May 14, 2009

im pretty purely germanic, and it doesnt apply to me either!
posted by freddymetz at 11:22 AM on May 14, 2009

My scalp hair and eyebrows are medium dark brown, beard is red, torso hair is black, and I'm blond from the pubes down. I think the wild variation is fairly common for Slavic types.
posted by bunnytricks at 11:27 AM on May 14, 2009

My cat has a black stripe down her back, blonde belly, and a brown stripey face. Lots of animals are all patchy- for instance, most fish, birds, and many mammals have coarser, darker backs & finer-textured, lighter-coloured bellies. I guess if you think about it, it'd make sense for human body hair to have some sort of colour & texture variation, too.
posted by pseudostrabismus at 11:53 AM on May 14, 2009 [2 favorites]

I think it's similar to why many of us have birthmarks and moles. Why is our skin not a uniform color or texture all over? I agree with pseudostrabismus...it's like patterns on animals. We're typically not striped, but many of us are spotted and have different patches of hair color.
posted by tastybrains at 12:26 PM on May 14, 2009

The difference with cat (and dog) hair color variation is that the skin out of which the different-colored hair grows is also a different color. In other words, if you shaved your cat bald, its skin would resemble its coat color. This is not the case with humans.
posted by pmbuko at 12:29 PM on May 14, 2009 [2 favorites]

I was in Vegas sitting poolside at the Bellagio. There was a, er, middle-aged gentleman that walked past with a rather full coat of hair on his back. In fact, it was enough to see that he had both brown and silver 'V' patterns in his back hair.

I doubt they were dyed there on purpose.
posted by SpecialK at 1:25 PM on May 14, 2009

i would go ahead and say *most* blonde haired people in the US have darker hair on their eyebrows and other places. Only the really purely Scandanavian and Germanic types seem to be blonde all over.

Yup. I'm more of a dark ash blonde now, but when I was a kid I was straight-up platinum blond -- with jet-black eyebrows. (I got accused of being a "bottle blond" a LOT when I was in my teens and 20's.) It had nothing to do with sun that I can tell -- you can even see this in my baby pictures.

Some people just have different colors different places; I just remembered a guy my parents knew when I was a kid who had a moustache that was brown except for one half-inch stripe on one side that was white.
posted by EmpressCallipygos at 1:34 PM on May 14, 2009

Well, my black hair is black everywhere.
posted by randomstriker at 2:17 PM on May 14, 2009

Given that hair should be the same all over

This is not even vaguely correct. You have hair everywhere except the palms of your feet and soles of your hands. Even bald guys have very fine hair on their heads. None of it needs to be the same colour, texture or anything. For example, I have dark brown hair on my head but do not have the same hair all over my face. You'd be very surprised if I did. The hair on my arms is different again as is the hair on my stomach and the hair in my eyebrows. All of these things are regulated by different sets of genes to give different types of follicles, as has already been mentioned, and this is totally normal. Assuming otherwise shows sloppy thinking, take an actual look at your own body and see how much normal variation there is and your basic assumption falls right over.

As an aside there's a good write up about when the genetic regulation is changed and long soft hair does grow all over the face in Mutants by Armand Marie Leroi. Really cool book.
posted by shelleycat at 2:57 PM on May 14, 2009

Well, my black hair is black everywhere.

And the hair on your forehead is the same as the hair on your head and in your eyebrows. Or not.
posted by shelleycat at 2:59 PM on May 14, 2009 [1 favorite]

Well, hair colour (in either location) is determined by the level of melanin being produced by the cells manufacturing the hair. There are different types of melanin, and they can be expressed at different levels at different locations within the body. Which means genetic variation is the simplest (although least satisfying) answer.

Note that melanin is also responsible for skin and eye colour, and although dark-skined, brown-eyed people usually also have dark hair, this correlation isn't perfect.

That being said, I've never heard of anybody with blond pubic hair that wasn't also blond (head) haired. This is a purely anecdotal observation, but there does seem to be a tendency for greater melanin production in pubic hair than regular hair. If I was to speculate as to why, I would guess that this was related to sex-hormones. As we all know, production of pubic hair is an indicator of sexual maturity. This implies that melanin production in pubic hair-producing cells is controlled by a different set of genetically-determined factors.
posted by kisch mokusch at 3:53 PM on May 14, 2009

I've always assumed that it was due to blood and lymph flowing to various parts of the body at different rates, carrying nutrients and hormones at equally variable rates. The pubic hair would be closer to major arteries (the big ones in the legs,) while eyebrows and such have a much shallower supply to draw from.

I have no scientific cites to provide, but as a guy who started going bald relatively young, yet who can grow a nice full beard in a couple of days, this explanantion has always made sense to me.
posted by metagnathous at 7:02 PM on May 14, 2009

The hair on my head is sandy blonde; tends to get towards light brown in winter, and tends to get truly yellow-blonde in summer if I spend a lot of time outside.

(A while back my then gf had a bottle of this spray-on hair lightener, which you simply mist on your hair, rub it in, then get in the sun or use a hairdryer to activate. Her brown hair was slightly changed when she used it, but when I tried it on a lark, and because my hair color is always riding a razor's edge in terms of color, in 10 minutes I had BLONDE hair. The kind of hair I had as a young child.)

My beard is red, auburn, blonde, brown and maybe a bit of black. My chest hair is dark brown. My pubes are brown with a hint of auburn. My eyebrows are light blonde. I am truly a genetic mutt. Which I think is the answer to your question--different races have different dominant genes, and there are separate genes for, say, your chest hair and the hair on your head.
posted by zardoz at 7:29 PM on May 14, 2009

What color is your underarm hair? I don't know anybody whose underarm hair isn't dark brown or black, regardless of hair color. Underarm hair and pubic hair are both related to secondary sex characteristics that develop during puberty.
posted by mynameismandab at 11:20 PM on May 14, 2009

What color is your underarm hair? I don't know anybody whose underarm hair isn't dark brown or black, regardless of hair color.
I actually took a peek after reading your comment, and my underarm hair is a medium brown. I'm probably lucky in that my leg hair has always been very sparse and light blonde in color. My eyebrows are a light-to-medium brown. I was curious because my head hair is naturally a honey blonde, but in the past 10 years or so it has actually become a slightly lighter blonde, and also has even "lighter" highlights in it. I rarely spend much time in the sun, and the only reason I can figure for the change (since I'm at the age when most of my contemporaries are going grey and I'm just getting blonder) is the 400mg of Plaquenil I take daily (and have been since 1989). One of the listed side effects is the blanching of hair. I wonder if this applies to all bodily hair?
posted by Oriole Adams at 11:40 PM on May 14, 2009

The pubic hair would be closer to major arteries (the big ones in the legs,) while eyebrows and such have a much shallower supply to draw from.

So why is your forehead hair a totally different colour than your eyebrow hair and your head hair? Your idea has no scientific merit at all and is totally made up, sorry.
posted by shelleycat at 12:40 AM on May 15, 2009

What color is your underarm hair? I don't know anybody whose underarm hair isn't dark brown or black, regardless of hair color.

You don't know enough people. Red or blonde underarm hair exists and is hardly a rarity.
posted by mu~ha~ha~ha~har at 2:55 AM on May 15, 2009 [1 favorite]

What color is your underarm hair? I don't know anybody whose underarm hair isn't dark brown or black, regardless of hair color. Underarm hair and pubic hair are both related to secondary sex characteristics that develop during puberty.

Two of my blond brothers have blond underarm hair and the third blond brother has dark underarm hair.
posted by deborah at 4:28 PM on May 15, 2009