Hair and Heredity?

[Capybara]

I was wondering about how children's hair color is sometimes completely different from their parents? My mom has red, curly hair with (natural) blonde highlights. My dad has black hair. I'm a "blondette," and my siblings hair ranges from red, to auburn, to platinum blonde, to dark brown. Not one of us, however, has the same hair color as either of our parents. I used to think that there were dominant and recessive genes for hair color as well as skin color, and would assume that (at least in my family's case) the black-colored hair gene would take over. This is clearly not the case, though.

What is it that truly determines a child's hair color? Are some colors dominant or recessive?

I'm not sure if there is another thread on this topic, but if there already is I apologize in advance :)

[Dreams_in_Pink]

i think pretty much everything about hair is hereditary. Even dandruff, my dad has it and so do i ^^; and yes, hair color solely depends on dominant and recessive genes. As far as i know, blonde is recessive and darker colours are dominant (like, red is dominant to blonde and brunette is dominant to red) this leads to interesting colors :) like, two brown-haired having redhead or blonde kids :D

[oceanwoman111]

In my family, we have a descent of German, French and Native American. It's really interesting because some of us have shiny, thick, black hair and eyes and some have really light blonde hair with blue or green eyes. Everyone else falls in between. I have dark brown hair with hints of red and green eyes. Always wanted my mom's thick, black, shiny mane though. It's funny how genetics works.

Dreams_in_Pink - I lived in Istanbul and Izmir for a year. I absolutely love Turkiye!

[*Rose Red*]

I am the only one in my family with my haircolor, I´m strawberry blonde. My dad had dark brown hair, and my mom had dark blonde hair like my sister and my brother, too. I don´t know why I´m so completely different, but I like it:D

[Sammich]

I'm the only one in my family with my hair colour.. err..
It seems hair colour also seems to... mix. o.o
I'm the only one in my family with dark brown hair, whereas my mother has black hair. My father has medium brown hair.

[pelicano]

My hair is the same colour (including eye colour also) as my grandmother's was, whereas neither of my parents are blondes or have blue eyes - my dad has kind of green eyes and ginger hair, and my mum is brunette with brown eyes.

I've inherited the seborrheic dermatitis from my mum though, and my sister had it too. Lucky us!!! :(

[Fractalsofhair]

I'm the first blonde in centuries to be in my family(Actually, as far as we can trace back with hair color. We've got photos of people born in the very late 1700s, in their old age, and people in my family gray late, so yeah. XD), though we might have had some blondettes. My hair color does seem to be changing. But I don't look at all like my dad's side of the family, and barely like my mum's side. I think it is recessive, but IIRC, hair color is controlled by more than 1 gene, basically it's not simple Punit squares, it's the more complex kind. That still doesn't explain why I'm the first blonde in quite some time, because chance would say that there's not a recessive gene, but random mutations can happen! I do have the hair texture of the rest of my family, which is split between fine and straight, one or two fine curlies, and coarse and wavy. My hair is slowly turning into the coarse and wavy thing, with the normal blue black hair(for my dad's side of the family, which proves I'm not adopted!), from the very fine straight blonde.

[Capybara]

Interesting! Thank you for all the replies, everyone!
So it must be just that certain genes which were recessive "came out of hiding?"
I've always wondered, too, why my mom has red hair. Apparently, the last person in her family to have had red hair was her mother's mother. So possibly my grandmother carried the red hair gene, but it didn't show until my mom came around.

From what you've all said, t sounds like I'm not the only one with a mish-mash of a gene pool! it does make for interesting, conversation-piece family portraits, though. My siblings and I all look like our parents, but the variation in hair color leads many people to believe that some of us use chemical dyes. Yay for diversity! :cheese:

[Renbirde]

Science warning! I tried to keep it simple, but there's only so much you can do with genetics. :)

Hair coloring works differently than skin color. For skin pigmentation, there are only two options-- with melanin or without melanin. For the purposes of this example, lets say you can be MM (extremely dark), Mm (Medium), or mm (white). The wide number of possible skin tones is due to the fact that skin color is a polygenic trait-- there are multiple copies of the gene controlling the final outcome. Instead of having one set of genes controlling the darkness of your skin, you have something like twenty. For example:

MM
MM
MM
Mm
Mm
mm
mm
mm
mm
mm
mm

That's 8 Ms and 14 ms. Cafe au lait. :)

Also, there is no way for a skin tone gene to be hidden. It is extremely unlikely to get an large difference in skin tone between the parents and their child without some sort of genetic mutation. If the parents were perfectly heterozygous (all their skin color genes were Mm), you might get a child who was very pale (or very dark) -- all or most genes mm (or MM), but the odds aren't good. :) Much more likely that the child will be within a few shades of the parents.


Hair is different. For starters, there are three pigments to play with-- Two types of eumelanin (brown and black) and pheomelanin (red). The science on hair color isn't as firm as that on skin color, but the best guess it that it's controlled by two genes: one is like the gene for skin tone-- red hair (recessive, r) or no red (dominant, R). The other displays brown (dominant, Hr) and blonde (recessive, Hl) alleles. I assume that's the gene that controls black pigment too.

So, if you have HrHr RR, you will have very red hair. The blond pigment won't hide the red.

On the other hand, in a family of black haired individuals, some may be carriers of blond and red-- the dominant black pigmentation hides the other colors. If said individuals have children, however, you could end up with kids that do not have black hair.

Hair color is really, really complicated. It's controlled by more than just genetics, and the genetics behind it are a tad complicated.

Here's the Wikipedia link (http://en.wikipedia.org/wiki/Human_hair_color#Genetics_and_biochemistry_of_hair _color), if I was too confusing. :)

[jera]

My hair color differs from my parents and most of my family members too, except for my paternal grandmother who was fair, freckled and had auburn hair. :)

[Kirry-Folk]

I don't have the same color as either of my parents, though my mother is also a redhead. I simply don't have her red hair. It sometimes seems both colors and textures can mix or be expressed simultaneously. Boyfriend has Filipino black hair and Scottish red highlights in his hair. Beard is red. My mom had stick straight hair and my father has like 4a mega tight coils (not kinky though). I ended up with wavy hair that isn't present in anyone else on either side of the family.

Genetics is crazy complex but fun!

[Miasen]

According to my granny I've got hair that's pretty much identical to her mom's (as in my great-grandmother). Neither hair nor colour is anything like my mom's. One of my sisters have hair just like our mom, and my other sister has hair just like our dad. Me, I dig my way back into the generation. ;) So yeah, definitely hereditary.

[anneisanne]

My skin tone is totally a throwback from my mom's side, but my hair is very much a mix of my mom's side and my dad's side. My mom has straight dark dark brown (well, nos it's salt-and-pepper) hair, and my dad has curly brown+red hair. I have wavy dark dark brown with red undertones.

I just hope that I go salt-and-pepper someday- my grandma still had brown hair and her mother never went gray!

[bumblebums]

Beautiful and clear explanation, Renbirde! Thank you.

I want to add just one thing: sometimes, unexpected features in offspring are the result of mutations, but there is also the serious possibility of maternal infidelity. Ahem. So it's not always a straightforward linear relationship between parents and offspring.

[Hana]

This ones tricky in my case - for my immediate family, at least!

I'm the only one in my family with thick hair, with the waves to the extent they are.
My parents and sister have much much thinner hair, with only slight waves to them.
While my sister has hair practically identical to my dads, mine is like neither of my parents, although I am going prematurely grey like my mother.

Which is odd. I dont know why this should happen - perhaps I'm particularly recessive?

[BlueMuse]

I got the huge bucket of recessive genes in my family. I had carrot red hair when I was little, still have green eyes, and I got some weird little genetic skin mutations that haven't been around for a generation or two. We know the green eyes came from my grandma, but no idea where the heck the ingrown muscle on my face popped up from, ah well, at least it looks like a birthmark.

[pelicano]

Hah, lucky for me I don't have to worry who my dad is - I look just like him, even if I do have different hair/eyes!:D

[grldollies]

Funny how the hair gene(s) toss turns out!

My Dad - Med-dark brown very curly, dads parents his mom Med-Dark brown & straight as a pin, his dad curly for sure & brown color I think.
My mom has wavy light brown if you ever saw it (blond till 13) but a bleach blond even at 72! I cant imagine her other then blond! Her Mom had very curly & very dark auburn hair and her Dad wavy med brown.

I have dark brown straight as a pin hair and my sister has dark brown very curly hair (ringlets around her face even).
If I do anything to my hair (lighten, perm or sun) the Red comes out, I don't like the red on me - hence I die it brown/black to eliminate the red. My sis on the other hand has no red under tones and loves red so she lightens her hair adding a hint of red tone....haha....go figure!

My Husband has straight med brown hair & both his mom & dad - straight brown hair. Our daughter has blond wavy hair! My DH had some great aunts that had blond hair!

- Gay : ) :puppykisses:

[Capybara]

Science warning! I tried to keep it simple, but there's only so much you can do with genetics. :)

Hair coloring works differently than skin color. For skin pigmentation, there are only two options-- with melanin or without melanin. For the purposes of this example, lets say you can be MM (extremely dark), Mm (Medium), or mm (white). The wide number of possible skin tones is due to the fact that skin color is a polygenic trait-- there are multiple copies of the gene controlling the final outcome. Instead of having one set of genes controlling the darkness of your skin, you have something like twenty. For example:

MM
MM
MM
Mm
Mm
mm
mm
mm
mm
mm
mm

That's 8 Ms and 14 ms. Cafe au lait. :)

Also, there is no way for a skin tone gene to be hidden. It is extremely unlikely to get an large difference in skin tone between the parents and their child without some sort of genetic mutation. If the parents were perfectly heterozygous (all their skin color genes were Mm), you might get a child who was very pale (or very dark) -- all or most genes mm (or MM), but the odds aren't good. :) Much more likely that the child will be within a few shades of the parents.


Hair is different. For starters, there are three pigments to play with-- Two types of eumelanin (brown and black) and pheomelanin (red). The science on hair color isn't as firm as that on skin color, but the best guess it that it's controlled by two genes: one is like the gene for skin tone-- red hair (recessive, r) or no red (dominant, R). The other displays brown (dominant, Hr) and blonde (recessive, Hl) alleles. I assume that's the gene that controls black pigment too.

So, if you have HrHr RR, you will have very red hair. The blond pigment won't hide the red.

On the other hand, in a family of black haired individuals, some may be carriers of blond and red-- the dominant black pigmentation hides the other colors. If said individuals have children, however, you could end up with kids that do not have black hair.

Hair color is really, really complicated. It's controlled by more than just genetics, and the genetics behind it are a tad complicated.

Here's the Wikipedia link (http://en.wikipedia.org/wiki/Human_hair_color#Genetics_and_biochemistry_of_hair _color), if I was too confusing. :)

This actually makes sense, thank you. Not *too* confusing :P I had no idea that hair color depended on so many pigments! And, when you add in the mixed ethnic backgrounds, I guess there are bound to be a wide range of hair colors.

As for paternity, well, all of my siblings and I actually look like our parents. We just have wonky hair colors :P

[ArienEllariel]

Both my parents have brown hair. My mom's is dark chocolate brown and my dad's is lighter. My hair is beginning to darken (but I have a feeling it won't be anywhere near my mom's color); it still retains some of the characteristics of my dad's (for example, if I go out in the sun, it lightens up pretty quick). My dad used to work outside a lot as a youth and his hair would lighten up to a reddish blonde. I wonder if that would happen with my hair? hmm.. I'm not much for summer heat so I don't know. ;)

[shadowclaw]

Beautiful and clear explanation, Renbirde! Thank you.

I want to add just one thing: sometimes, unexpected features in offspring are the result of mutations, but there is also the serious possibility of maternal infidelity. Ahem. So it's not always a straightforward linear relationship between parents and offspring.

Ok, this doesn't have anything to do with hair, but it does have to do with genes.

Did you know that two light skinned people can produce an offspring with very dark skin? An instance of this could easily lead the husband to believe that his wife was unfaithful to him, when really it means somewhere back a few generations, someone married someone with dark skin and the trait stuck around. There are also some instances where twins from mixed race parents end up having two different skin colors. Genetics are awesome!

As for hair, I think Renbirde did indeed give a good explanation. Even hair texture behaves like this. My mother and my sister's father both have pin-straight hair, but my sister's hair is curly. Or rather, it got curly as she got older. It used to be stick straight. We're waiting for it to turn red next, because our grandmother's hair is curly and red (or at least it was red before she went gray).

[froglet]

I have the exact same hair as my Mother, shade, texture, even our gray's look the same. It was hard to tell until I started to gray as my Mother and Father both had long, straight, dark hair. I inherited my skin tone from my father, a light to medium toned olive. My eyes are hazel as were my maternal Grandmother's, a pretty golden-green with dark gray accents. Both of my parents eyes are dark brown. Not too bad, gene pool wise. :grin:
My sister Zanne, has dark blond, very wavy hair and a different skin tone, hers is yellowish as opposed to olive. Henna looks great on her, but terrible on me.

[loralie]

My father had a genetic defect called Waardenburg Syndrome (http://en.wikipedia.org/wiki/Waardenburg_syndrome) which presents in hearing loss, facial defects and poliosis (depigmentation of skin or hair). My dad didn't have too noticeable facial defects but he had a streak of pure white hear and was nearly deaf. My half sister inherited the streak of hair as well.

I've been tested but do not have the syndrome but always admired that strange streak they had... I ended up with my mom's mousey brown. She does have lovely grays coming in when she doesn't colour. At 21, I'm in no huge rush but I think they're beautiful!

[Leena7]

I think hair color could be similar to eye color, meaning that it is determined by multiple genes and combinations. Sometimes mutations also occur. A child will not necessarily have either of their parents eye colors or hair colors.

[Prettychild]

My hair is black (I am from South America originally) and my husband is British. His hair is darks brown with grey (but was blond as a child). Our son has reddish blond hair.
About genetics: My mum went gray in her thirties, and I've had gray since I was 6 years old! Started with 3 white hairs on the crown of my hair and then spread. However, every one in my family has a funny wavy lock starting at the forehead (much like a horse's forehead lock) and baby has it too!

[hydrangea]

I have my dad's hair. Fine/dark blonde. My mom's hair is brown with red hues and coarse. It would be interesting to find out what color/texture/etc.. even terminal length is dominant and which is not.

[Prettychild]

I have my dad's hair. Fine/dark blonde. My mom's hair is brown with red hues and coarse. It would be interesting to find out what color/texture/etc.. even terminal length is dominant and which is not.


I agree, it would be interesting to do a poll. I have seen many of the pics in the forum and many many brown-blonde hair. Having said this I have seen many Indian ladies with amazing long hair. I think it is not colour but thickness that makes a difference. Thick hair shaft will probably be more resistant to breaking/snapping, more able to handle the weight of a long mane?