Where does my baby get her red hair?

June 23, 2008 8:08 PM

Where does my baby get her red hair?

To the recollection of all living relatives, only one person in her line of ancestors has red hair... and that's her father's great grandfather. I'm blonde and hubby has brown hair. This is copper red hair we're talking about, not some strawberry blonde or auburn flim flam. Just trying to give some kind of answer to the oft asked question, "Where does the red hair come from?"

I'm wondering how the red hair gene works... is it recessive and require two chromosomes to appear? I understand that we each donate one chromosome to make a baby. Do they both have to be red? Does blonde hair trump red hair?

I'll be checking in to provide more info if needed.

posted by vermontlife to health & fitness (40 comments total)

My youngest is a redhead and we don't recall anyone on either side of the family having it...but my understanding is that it is a recessive gene. So obviously we are carriers.

I have black hair and hubby has brown. My son's hair is auburn and my other daughter is blonde. Go figure.


Do you have Irish ancestry? I think that is probably a given!
posted by konolia at 8:14 PM on June 23, 2008

How old is your baby? Ours was born with red hair, but it all fell out when she was about seven or eight months old and the hair that grew back in was light brown without a single trace of red.
posted by briank at 8:21 PM on June 23, 2008

I was going to give a similar answer to briank. When I was a very young child, my hair was close to platinum blonde. Now, it's closer to what my hairdresser refers to as "light ash brown." In otherwords, barely blonde if at all.
posted by Afroblanco at 8:23 PM on June 23, 2008

No one in your family now is redheaded - but were any of the adults (grandparents, for instance) redheaded as infants or very young children? Would you know if they had been? In my family it's fairly common to have red or even very pale blond hair as a small child, and then darken to dark brown by adulthood - but it isn't particularly remarked by anyone. Someone outside the family pointed out that it was odd or I would never have thought about it.
posted by dilettante at 8:23 PM on June 23, 2008

Hair changing from light blonde to ash-brown (or mouse-brown) is fairly common in Caucasian populations (at least where I grew up). Also common is eye color being bright blue at birth and changing to brown as the child ages.
posted by infinitewindow at 8:28 PM on June 23, 2008

dilettante makes a good point. the guy i'm dating now had beautiful bright coppery-red cork-screw curly hair through his mid twenties. he's in his early twenties now and his hair is now brown. however, his facial (and other bodily hair) still grows in red.
posted by violetk at 8:32 PM on June 23, 2008

Yep, in a majority of cases, you need two copies of the recessive "redhead" gene to be a redhead, which means that generations of non-redheaded carriers can go by before the magical colour reappears. This wikipedia article does a decent job of laying out the basics.

Having said that, I also have a little brother who had red, red, red hair as a baby, and that eventually turned into a sandy blond colour.
posted by Hellgirl at 8:36 PM on June 23, 2008

Red hair is recessive.

My mother's hair was dark brown. My dad's hair was black. They had three kids and all of us are redheads.

None of our grandparents were redheads, either, and no uncles or aunts, but red hair is known to have appeared in both family lines. (I think that one of my maternal great-aunts was a redhead but I'm not really sure.)

Recessives like red hair can lurk in the background, completely unexpressed, for generations and pop out when you least expect them. As you say, the kid has to get the gene from both parents.
posted by Class Goat at 8:38 PM on June 23, 2008

The mailman?

Yeah, it's a famous example of a recessive gene. It's in the family tree, but not necessarily on a branch that's nearby.

Be happy. That's a magic baby.
posted by rokusan at 8:51 PM on June 23, 2008

Well, someone had the be the first redhead, so it's either a mutation, or it's a recessive thing handed down from prior generations.
posted by pmbuko at 9:03 PM on June 23, 2008

my hair changed from light blonde to almost black as an adult.
posted by drjimmy11 at 9:05 PM on June 23, 2008

Like violetk my brother was a redhead until his teens, now he has sort of blah coloured brown hair (we call it hair coloured hair), but his beard is totally red. Sort of weird looking really. My mom is a ginger though. So not so much a mystery there. Other babies in my family have grown out of it before their 1st or 2nd birthdays.
posted by heavenstobetsy at 9:13 PM on June 23, 2008

A bunch of redheads, myself included, popped up in my generation on my mom's side--none had been seen for several generations, but her family is Scottish.

It is a two-recessive gene trait, so all of our dads have it somewhere in their background. Although my mom used to say I got it from the milkman, until I repeated it at church (in answer to the dumb question "Where did you get that reeeeed hair!?!").

I married a bald guy and ended up with a blonde and a brunette. Data point?
posted by padraigin at 9:19 PM on June 23, 2008

Interesting that so many people say that their red hair changed to non-red later on in life. I heard that my whole life and figured mine would too. Still red as ever at 24.

I don't think you need a special formula for red hair other than two carriers of the gene. My parents have brown and dark brown hair.
posted by GooseOnTheLoose at 10:00 PM on June 23, 2008

I think the red hair gene is a trickster. It hides out in the DNA shadows, waiting to make its presence knows. IIRC, the short answer is that red hair is a simple combination of blonde and brown/black hair. You plus your hubby equals redhead baby.

My father's mother had red hair, but my dad's was black as night (it's grey now). His complexion, though, was somewhat that of a redhead--freckles, fair skin. I had really blonde hair as a child, and since puberty it's mellowed to a kind of ashy blonde. But depending on the light and how much time the sun bleaches it out, my hair swings from true blonde to almost dark brown, and even strawberry blonde if the lighting is just so. The real kicker, though: my beard is red.
posted by zardoz at 10:04 PM on June 23, 2008

Interesting... you learn something new every day. I have been reading the various responses about people's hair colour changing later in life and I honestly didn't expect that a light blonde would switch to almost black.

Not to derail the original question, but how and why exactly does that change happen?
posted by madman at 10:09 PM on June 23, 2008

I don't know why hair changes--my husband's hair, when he had it, started out pale blonde and darkened to brown. Now he's got a varicolored beard. We expect our blonde's hair to eventually darken, but who knows? Some of the blonds in his family have stayed blond.

My redhaired cousins are bright orange carrot tops, and my hair has always been a somewhat darker auburn, with dark brown eyebrows, so it was assumed my hair would darken over time. It never did.

I imagine it's hormonal, the changes in color and texture, given what happens to some people as they go through puberty and pregnancy and menopause.
posted by padraigin at 10:21 PM on June 23, 2008

I'm another who had red hair as a kid. It went from clown-wig red (and curly!) to straight brown hair. Just a data point.
posted by flibbertigibbet at 10:36 PM on June 23, 2008

My blond mother and dark-haired father beget me, carrot-top until age four, when it lightened to strawberry blond, then auburn with brown eyebrows when puberty hit. Supposedly there is a great-grandmother on my mother's side of the family with red hair, but the link is so tenuous that I've always secretly (til now) theorized that redheads come from blond & darkhaired parents.
posted by annathea at 11:59 PM on June 23, 2008

I know I'm not mentioning anything new at this point, but I had really curly red hair as a baby, which became very straight light brown hair when I was in elementary school, and by high school I had wavy dark brown hair.
posted by arianell at 1:14 AM on June 24, 2008

I have brown eyes and my parents, all grandparents and great grandparents have bright blue eyes.

Just another example of a genetic mutation. It does also make me magical too.


just a little
posted by Neonshock at 1:33 AM on June 24, 2008

I was born with dark reddish hair, and was fairly red headed through about the age of 4 or 5. Then I was sort of brownish blonde and now I seem to have achieved whatever color is in the middle of a brown-red-blonde Venn diagram. I let people tell me what color my hair is; if I try to say blonde or red or anything definitive, I inevitably find that the other person has a very different opinion.
posted by MadamM at 2:37 AM on June 24, 2008

The Wikipedia Red Hair page is very informative and will tell you about all the genetics. There is also potentially useful information for you on stuff like pain tolerance, etc. Although only 1-2% if the world's population has red hair 13% of those here in Scotland have it and about 40% of the population carry the recessive gene. Ireland is pretty much the same.
posted by rongorongo at 3:43 AM on June 24, 2008

My mother told me that, as I was born, the obstetrician said, "Where did all this red hair come from?" My brunette parents apparently had red-headed ancestors. So does your daughter.
posted by Carol Anne at 5:21 AM on June 24, 2008

My mom was a redhead, my dad's hair is black - but it was blond until he came back from Vietnam, and then it grew in "Indian black" as the family says. Red hair crops up in my family pretty much every other generation - so if I were to have kids, it would be likely for them to have red hair, also because my husband was redheaded as a child, but now has black hair.

FWIW I am the only person in my entire extended family to remain blonde over my lifetime. I am 29 this year and my hair is still very, very blonde, and I do not bleach. Both blonde and red are recessive. I am, however, 25% Scottish.
posted by Medieval Maven at 5:34 AM on June 24, 2008

Red hair (and blond for that matter), freckles on the body, and freckles on the face all require separate mutations on MC1R. I got all three, the only one in the family as far as anyone can remember with ANY of the traits, but I've got two other rare traits that link me to my dad so it's not a question of my mom cheating. I believe there are 16 alleles on MC1R, which means both of my parents had to be carrying three compatible recessive mutations on those alleles to get me. The odds should be astronomical of two people like that finding each other randomly, but here I am, and judging by the above there's a lot of us out there.

It really adds to movies like X-Men where human mutants are part of the plot line. It's silly. We're all mutants. Even MC1R extends beyond hair and freckles: "both genotypes display reduced sensitivity to noxious stimuli and increased analgesic responsiveness to morphine-metabolite analgetics." I've also heard surgical anesthesiologists increase the dosage on female red heads by 10% because anesthetics don't work as well on them.

... and that's just on one gene of the 20,000 - 25,000 genes humans have. Personally I'm holding out for wings and super strength, but MC1R was a good first step for comic book greatness. ;-) BTW - after three decades my hair has turned mostly brown with a reddish tint now, but my beard is still red and blond. I started fire engine red so not bad. The change is apparently down to something called gene expression.
posted by jwells at 5:49 AM on June 24, 2008 [4 favorites]

P.S. We actually HAD a mailman with red hair and freckles. My mom used to use that joke on the neighbors just to get a rise out of 'em.
posted by jwells at 5:53 AM on June 24, 2008

Interesting... you learn something new every day. I have been reading the various responses about people's hair colour changing later in life and I honestly didn't expect that a light blonde would switch to almost black.

Not to derail the original question, but how and why exactly does that change happen?

Very, very gradually, in my case. I was blond as a kid, and every year it seems like my hair gets a bit darker. Not black, per-se, but definitely "hair-coloured hair".

Some kids are born with one hair color, which falls out and another color grows back in during babyhood.
posted by muddgirl at 5:56 AM on June 24, 2008

Another 'data point'. As a baby my mom had black, black hair. It all fell out as she approached her first birthday and grew back blonde. She stayed blonde from then on (though now its going grey, can't escape that change!).
posted by sandraregina at 6:08 AM on June 24, 2008

All it takes is two recessive genes.
posted by cellphone at 6:35 AM on June 24, 2008

I've actually (slightly) went in the opposite direction of some in this thread. I have brown/black hair, but as I've gotten older, when I grow out my beard, I'll get clumps of red hairs. My biological father supposedly had red hair though.

Is it true that red hair is limited to only certain cultures (Irish, Scottish, and IIRC Nordic?)?
posted by drezdn at 6:58 AM on June 24, 2008

The same question as answered by a geneticist.


Is it true that red hair is limited to only certain cultures (Irish, Scottish, and IIRC Nordic?)?

Africans can have it too, but by a different mechanism.

I have an interest in red hair because it appears red hair may be a marker for people who require a little extra anesthesia.
posted by TedW at 7:58 AM on June 24, 2008 [1 favorite]

In Mexico I was amazed at how many redheads I saw. It was jet black hair but with a reddish tint. I asked a few if it was colored and it wasn't. It *could* be traces from Celtic influences in northern Spain, but it was so common I figured it was just universal at that point.
posted by jwells at 8:11 AM on June 24, 2008

Two things to mention. First, the genetics of red hair, like many other things, are more complicated than I think Wikipedia and others are presenting here. It unfortunately is not as simple as the simple dominant/recessive gene dichotomy you may have learned in school.

This review of the MC1R literature reveals that it is not a simple single-factor control of red hair. While most redheads (>80%) have two copies of a MC1R variant, most of the rest have only one, and some even have zero copies of identified red-hair–causing MC1R variants.

More importantly, there are people who have one or two copies of MC1R variants yet do not have red hair. So MC1R, by itself, does not entirely control the presence of red hair, although it is a good signal for it—you are 20× more likely to have red hair if you have two copies, and 6× more likely if you have one. This means it's possible that your child's red hair is caused by an interplay between several genetic factors which coincide in her for the first time, without it showing up in multiple ancestors.

The other possibility is that there is a non-paternity event in your genetic pedigree. There is the distinct possibility that one of your baby's male ancestors is not who you think it is, although estimating this is difficult. This study estimates a 3.7% nonpaternity rate for a sample of Albuquerque men, but did not test them directly.
posted by grouse at 8:21 AM on June 24, 2008

I honestly didn't expect that a light blonde would switch to almost black.

That happened a few times in my family, too. My mom famously went from blond and curly to dark brown and straight when she was about 13. She got in trouble at school for "dying" her hair, because it was all streaky for a time. (It was 1950 and catholic school, they were pretty strict.)

The same deal happened to my brother, but he was younger when it changed. The rest of us have various shades of brown hair, although I got the curls and still have them. None of us had red hair, though.
posted by cabingirl at 9:24 AM on June 24, 2008

Platinum blonde to dark, dark brown here, the change occurring at about age seven.
posted by HotToddy at 10:17 AM on June 24, 2008

I've also heard surgical anesthesiologists increase the dosage on female red heads by 10% because anesthetics don't work as well on them.

I've never had a general anesthetic, but my dentists and endontist could tell you a tale of just what a hellish patient auburn-haired me is to work on. Red haired people also have thinner skin and thinner gums. I've been known to hit the ceiling during a cleaning. The time I had a root canal it took 12-14 needles to freeze me enough for the procedure.
posted by orange swan at 11:15 AM on June 24, 2008

Another data point on color change: I was born with a full head of curly black hair, which fell out after a few months. The next color was platinum blonde (and straight) which has gradually darkened over the course of my life. I'm 25 now, and still generally called blonde, but it's much, much darker than it used to be. My eyelashes are pitch black, and my brows are medium brown.

Also, I was born with blue eyes, which darkened to brown.
posted by dizziest at 11:56 AM on June 24, 2008

For what it's worth, I knock out like a dream. Cheap date!
posted by padraigin at 12:23 PM on June 24, 2008

There are no redheads in my immediate (or even further out) family other than me. My mother couldn't understand it until they went to a family reunion when I was a baby and...redheads!
posted by FlyByDay at 8:17 PM on June 24, 2008