We Still Don’t Know Why Some People Get Freckles

If you're like me—that is, a person with freckles—you've probably been subjected to deludes of ridiculous anti-freckle propaganda in your life. From schoolyard teasing to creams to that claim to erase every last speck off the bridge of your nose, us freckle-faces have seen it all.

Partisan views aside, there's a lot we know about how freckles are formed, and what they're made of. But, as a new episode of SciShow explains, we still aren't sure why some people get them.

Here's what we do know: Freckles are tiny areas of our skin made up of high concentrations of melanin. Melanin is a pigment produced by the cells in our skin, eyes, and hair, and is responsible for giving them, well, pigment. Humans need melanin because of its photoprotective properties that help to shield us from UV rays and free-radicals.

For people sans freckles, melanin is produced evenly throughout the skin, the video notes. But for those of us with them, melanin will tend to cluster in little clumps that darken whenever we spend a day outside in the sun. Freckles aren't permanent, however, and we're not born with them. The less we're exposed to sunlight, the more freckles will fade.

Sometimes freckles are confused with other pigmentation conditions called lentigines (also known as "liver spots"). Unlike freckles, lentigines appear on some people because their skin simply contains more melanocytes, which are the skin cells that produce melanin. They're also permanent, and won't fluctuate with a person's exposure to UV rays.

We also know that freckles are linked to a key genetic determinant for skin and hair color, which is a gene called MC1R. This particular gene tells our cells how to make a specific protein that's involved in the production of melanin.

Our bodies create two types of melanin called eumelanin and pheomelanin. If your MC1R gene is working as it should, your body will produce more eumelanin, which results in darker hair and skin. However, if that gene is malfunctioning, the narrator explains, you'll produce more pheomelanin, making you more likely to have fairer skin, red or blonde hair, and freckles.

But here's where it gets a little tricky: Red hair and freckles aren't inseparable. Red hair is a recessive trait, and freckles are dominant. Both red hair and freckles run in my family. I only inherited the latter.

Geneticists suspect the number of copies of the MC1R gene a person has will determine whether or not they'll end up with red hair or freckles, or both. Since everyone is born with two copies of most of their genes, scientists have suggested the combination of various functioning and malfunctioning MC1R genes is the determining factor in which traits a person will end up with.

So even though both features are thought to be controlled by the same gene, there are likely multiple genetic stressors at play here.

For seemingly simple little flecks of color smattered across some of our faces, freckles are pretty complicated. But if there's one thing we know for sure, it's that freckles aren't a bad thing. If you want 'em but don't got 'em, maybe try some Freckle Juice.