When it comes to how similar twins will look, it depends on a variety of factors. Some twins truly look identical while others don’t even look like twins.
Can twins have different hair colors? Yes, twins can have different hair colors. While it’s more common for fraternal twins to have different hair colors than identical twins, it’s still possible for both types to come out with different hues on their heads.
Due to influences from biology and/or environment, twins can be born with different hair colors or develop different hair colors over time. If your twins do have different hair colors, there could be many reasons why.
Hair Color Differences in Twins
Most people assume twins will look exactly alike or very similar. However, there are different types of twins, and this can greatly affect how similar their features will actually be when they are born.
Fraternal Twins and Hair Color
Fraternal twins come from two different eggs fertilized by two different sperm. Since fraternal twins can actually be boy/girl, it’s obvious that something like hair color can easily be different.
Fraternal twins don’t share any more DNA than any other siblings born at different times, so their features can vary just as much. While some will have the same hair color, some won’t.
Identical Twins and Hair Color
Identical twins come from one fertilized egg that splits. That means they share almost exact DNA, and that includes hair color.
There can be an anomaly that causes one identical twin to have a different color than a twin sibling, but it’s rare.
Identical twins may not look exactly alike, but their differences tend to be much more subtle.
However, recent studies do show that out of 300 identical twins in a study, only 38 had the exact same DNA. This does leave plenty of room for physical differences to emerge.
Factors That Cause Hair Color Differences in Identical Twins
There are a couple of reasons that identical twins might have different hair colors. Some of these happen in the womb, and some occur on the outside.
Identical twins have almost the exact same DNA, but there can be small differences.
After the egg splits, cells that develop into the babies can have gene mutations that affect how identical they look. In rare cases, this can affect something as major as hair color.
Skin color and eye color can also be impacted by gene mutations in identical twins.
Once identical twins are out of the womb, their appearances can change based on external factors. A twin who spends more time in the sun may have lighter hair than the twin who stays inside.
Identical twins are also free to intentionally change their looks to stand out from their twin siblings. It’s easy to dye hair a different color, and some twins may do this to avoid being mixed up with their twin siblings.
Why Do Fraternal Twins Look Different?
Fraternal twins can look very similar or extremely different. The reason is that they are only as genetically similar as non-twin siblings.
Fraternal twins come from two eggs fertilized by two sperm, so they won’t share 100% of their DNA. While same-sex fraternal twins might look similar, they also may not look anything alike.
When you have boy/girl fraternal twins, they could have similar features, but most people might not even know they are twins by just looking at them.
Can Identical Twins Have Different Hair Texture?
For the most part, identical twins will have very similar features. It’s highly unlikely for them to have different hair texture because they come from the same fertilized egg. However, it can happen.
Common Slight Differences in Identical Twins
While gene mutations in the womb can lead to major differences in the way identical twins look, it’s much more common for there to be very slight differences.
Identical twins are so genetically similar that their physical appearance is likely going to be close to the same with a few small exceptions. A good example is the case of mirror twins.
Freckles or Moles
Identical twins do not always have freckles and moles in the exact same places on their bodies. In fact, if one twin has a freckle that another one doesn’t in plain sight, this can be an easy way to tell them apart.
Identical twins may have birthmarks in different places that are not shaped the same.
Shape of Features
Though it may be hard to see at first, even the faces of identical twins can be shaped differently. This is true with all of their features.
While it may be impossible for someone who doesn’t live with twins to notice, one child may have a rounder face while the other child’s is more oblong. These differences can become more pronounced over time.
Identical twins can also be mirror image twins. While only 25 percent of identical twins fall into this category, it helps caregivers tell them apart.
Mirror image identical twins are what they sound like. If you face these twins toward each other, it’s like they are looking in a mirror. One will have a freckle on the right cheek while the other has the freckle on the left.
This can also extend to things like what hand each one writes with and, in rare cases, can even affect the placement of internal organs.
Can Fraternal Twins Look Identical?
Fraternal twins who are the same sex can look identical. Actresses Mary-Kate and Ashley Olsen are a great example of this. They are fraternal twins but have been mistaken for identical twins their entire lives.
Though fraternal twins share the same amount of genes as other siblings who are not twins, they can still look remarkably similar.
Do Fraternal Twins Have the Same DNA?
Fraternal twins do not have the same DNA. Fraternal twins come from two eggs fertilized by two different sperm and share about 50% of their DNA, same as any non-twin siblings.
Twins, especially fraternal twins, may not have the same hair color, and now you know why. This can make them easier to tell apart.
Kristy is the mother of four, including identical twins. With a background in education and research, she is constantly learning more about parenting and raising multiples. When she has spare time, she enjoys hiking into the woods with a great book to take a break.