Prenatal estrogen linked to red hair, green eyes/ more divergent traits

[Maria Sharapova]

Seems as though red hair and green eyes are the most feminized of all the hair and eye colors.


Of the ‘new’ hair and eye colors, red hair diverges the most from the ancestral state of black hair and brown eyes. It is the most sexually dimorphic variant, not only in population frequency but also in health outcomes.


Prenatal estrogen particularly seems to favor red hair. According to a twin study, women are likelier than men to have red hair even when the genotype is the same. Prenatal estrogen may also affect eye color. Face shape is more feminized in blue-eyed men than in brown-eyed men of the same ethnic background. In addition to favoring blue eyes over brown eyes, prenatal estrogen seems to favor green eyes over blue eyes, the so-called blue-eye genotype being expressed in women more often as green eyes. In sum, there seems to be a general tendency for women to exhibit less frequent hair and eye colors at the expense of more frequent ones.

In terms of hair color it seems as though prenatal estrogen favours red hair>blonde hair>brown hair>black hair in that order.

In terms of eye shape it seems to favour green eyes most in the order of green eyes>blue eyes>brown eyes.

https://www.biorxiv.org/content/10.1101/139295v1.full

[Joso]

Blacks are dark but not masculine because they are tropical adaptated.
Don't forget that is the brain that matters the most.

[Maria Sharapova]

Blacks are dark but not masculine because they are tropical adaptated.
Don't forget that is the brain that matters the most.
I think the study focused on Caucasian groups. I think it holds true for Caucasians.
And prenatal hormones influence the brain/personality as well, it's all relative.

[Joso]

I think the study focused on Caucasian groups. I think it holds true for Caucasians.
And prenatal hormones influence the brain/personality as well, it's all relative.

Caucasian concept doesn't makes any sense. EV-13 caucasoids are like blacks for example, tend to be tall and thin, tropically adaptated too.
And yes, it is true but brains don't work all in the same way, not all equal, there is enough evidence for that.

[Luso]

Yeah no wonder I got almost black hair. I am all testosterone baby :rolleyes:


On a real note, does that mean people with red hair/blonde hair tend to have more estrogen than guys with black/brown hair? -- obviously we are talking about cacausoids.

[Maria Sharapova]

And yes, it is true but brains don't work all in the same way, not all equal, there is enough evidence for that.
True but I'm talking in terms of averages. Prenatal hormanes won't influence everyone the same way but on average you will start to see a correlation b/w certain hormones and there influence on the brain.

[Joso]

True but I'm talking in terms of averages. Prenatal hormanes won't influence everyone the same way but on average you will start to see a correlation b/w certain hormones and there influence on the brain.

Yes but the brain shape and size as well as functioning is more important to make such conclusions, certainly more than eye and hair colour.

[Maria Sharapova]

On a real note, does that mean people with red hair/blonde hair tend to have more estrogen than guys with black/brown hair?
It means that in theory it's more likely they had been exposed to lower levels of testosterone in utero. This isn't the same as current circulating levels of hormones they will have when they are adults but it could play a part. But I guess you could say that the prenatal environment 'plants the seed' for future profiles.

[Joso]

True but I'm talking in terms of averages. Prenatal hormanes won't influence everyone the same way but on average you will start to see a correlation b/w certain hormones and there influence on the brain.

dark caucasoids tend to have smaller and or less vision based brains.

[Joso]

It means that in theory it's more likely they had been exposed to lower levels of testosterone in utero. This isn't the same as current circulating levels of hormones they will have when they are adults but it could play a part. But I guess you could say that the prenatal environment 'plants the seed' for future profiles.

I know some people that used to have green eyes that turned to blue.

[Joso]

I know some people that used to have green eyes that turned to blue.

Maybe it was an illusion, idk