Are Dark Eyes More Dominant? The Genetics You Never Noticed

The basics: what determines eye color anyway?

Honestly, I used to think eye color was just... well, random. Like, my mom has brown eyes, my dad has blue, and I ended up somewhere in between—classic hazel confusion. But eye color is actually a complex trait influenced by multiple genes, not just a single dominant or recessive switch like we learned in high school biology (thanks, Punnett squares, but you oversimplified everything).

The two major players here are the OCA2 and HERC2 genes, which are responsible for producing melanin in the iris. More melanin = darker eyes. Less melanin = lighter eyes.

So is brown really dominant?

Yes, brown eyes are typically genetically dominant, at least when compared to blue or green. This means that if you inherit a brown-eye gene from one parent and a blue-eye gene from another, you're more likely to have brown eyes. Simple, right? Well, not exactly...

The twist: it’s not always that predictable

Multiple genes, more combinations

Well, here’s the kicker: more than 16 genes can influence eye color. That means you might carry some wild card alleles from your grandparents or even further back. I had a friend, Sofia—her parents both had brown eyes, and she popped out with blue eyes. Everyone was like, “Wait, is the mailman blonde?” But nope—it’s just how complex inheritance can get.

This breaks the old-school dominant/recessive rule just enough to mess with your expectations.

Green eyes: the mysterious middle child

Green eyes, by the way, are even rarer and weirder. They're sort of a halfway point between blue and brown, and usually result when there's a moderate amount of melanin. Genetically, green is kind of recessive—but also not as recessive as blue. (Confused? Yeah, me too.)

Are dark eyes more common globally?

Oh yeah, 100%. Over 75% of the world’s population has brown eyes. And in some regions—like Africa, Asia, and South America—that percentage jumps to like 90% or more. Brown eyes are not just more dominant genetically, they’re also way more common demographically.

Blue eyes, on the other hand, are mostly concentrated in Northern Europe. Fun fact: it’s believed that all blue-eyed people share a common ancestor from around 6,000–10,000 years ago. Kinda wild, right?

Does having dark eyes come with any “advantages”?

Physically speaking

Actually, yeah. Dark eyes have more melanin, which offers some protection against UV light and possibly even certain eye diseases. So if you’ve got brown eyes, your retinas might thank you when you're older. I mean, it’s not superhero vision or anything—but still, a win’s a win.

Socially speaking

Well… here's where things get interesting. People often project meanings onto eye color. I once had a roommate, Alex, who swore that “blue-eyed people are more trustworthy.” Total nonsense—but it shows how much cultural bias can play a role.

In some cultures, dark eyes are seen as warm and grounded; in others, mysterious. In any case, it’s not about the biology—it’s about perception. And perception is messy.

So, are dark eyes more dominant? Final thoughts.

Yeah, in the classic genetic sense, dark eyes—specifically brown—are more dominant. They tend to win out in the gene lottery when paired with blue or green. But dominance doesn't mean "better," just more likely to be expressed.

What really sticks with me, though, is how complex and beautiful this variation is. Whether your eyes are deep brown, icy blue, stormy green, or some mix that can’t be pinned down, there’s a genetic story behind them. And sometimes, that story surprises even the scientists.

So next time someone says, "Oh, brown eyes are boring," just remember: they’re dominant for a reason—and full of secrets.

Is 165 cm normal for a 15 year old?

The predicted height for a female, based on your parents heights, is 155 to 165cm. Most 15 year old girls are nearly done growing. I was too. It's a very normal height for a girl.

Is 160 cm too tall for a 12 year old?

How Tall Should a 12 Year Old Be? We can only speak to national average heights here in North America, whereby, a 12 year old girl would be between 137 cm to 162 cm tall (4-1/2 to 5-1/3 feet). A 12 year old boy should be between 137 cm to 160 cm tall (4-1/2 to 5-1/4 feet).

How tall is a average 15 year old?

Average Height to Weight for Teenage Boys - 13 to 20 Years

How to get taller at 18?

Staying physically active is even more essential from childhood to grow and improve overall health. But taking it up even in adulthood can help you add a few inches to your height. Strength-building exercises, yoga, jumping rope, and biking all can help to increase your flexibility and grow a few inches taller.

Is 5.7 a good height for a 15 year old boy?

Generally speaking, the average height for 15 year olds girls is 62.9 inches (or 159.7 cm). On the other hand, teen boys at the age of 15 have a much higher average height, which is 67.0 inches (or 170.1 cm).

Can you grow between 16 and 18?

Most girls stop growing taller by age 14 or 15. However, after their early teenage growth spurt, boys continue gaining height at a gradual pace until around 18. Note that some kids will stop growing earlier and others may keep growing a year or two more.

Can you grow 1 cm after 17?

Even with a healthy diet, most people's height won't increase after age 18 to 20. The graph below shows the rate of growth from birth to age 20. As you can see, the growth lines fall to zero between ages 18 and 20 ( 7 , 8 ). The reason why your height stops increasing is your bones, specifically your growth plates.