Why do many fraternal twins look identical?

Question

I know at least three sets of technically fraternal twins who look identical. Why is this?

I'm not talking about fraternal twins who just happen to look alike because they're the same age. I'm talking about fraternal twins who look so identical few can tell them apart. Yet in utero, they were in separate sacks.

Answer 1

I would love to know this too. My twins are now 4yrs. I have recently been told they may be fraternal when we thought they were identical. The Dr doesn't seem to understand why we want to know and wont test them.

Answer 2

Sometimes, two brothers or two sisters look a lot alike. The fraternal twins are genetically no more similar than any pair of siblings, but they just happen to be the same age, so will seem more alike.

Whether a set of twins are identical or fraternal shouldn't really matter unless one of them is affected by some possibly genetic condition. Then, it might be important to actually have them tested to determine which they are...

Answer 3

They may be identical twins, and either not know about or believe their "identical" status, or, for reasons of asserting individuality, lie about it (like the Olsen twins).

The only way to check for identical/fraternal would be a DNA test. Have these twins had the test?

Answer 4

fraternal twins are still siblings with the same set of parents some time regular siblings looks so similar that if they were the same age they would have been identical. since they share the same genetics fraternal twins have a really good chance to look alike.

I hope this helps

Answer 5

The cues by which people learn to differentiate one person from another are very subtle--it's why people of one race often have trouble differentiating people of other races with whom they don't interact on a daily basis. Also, age and environment play a large role in how we look, and how we identify others. Think of how people often see a photo of one of their grandparents as a child, and remark how much the photo looks like them.

It is very common for people to look very similar to their parents and even their grandparents or cousins. If both parents are from similar ethnic backgrounds, they will already have a great deal of overlapping genetic material. Fraternal twins share 50% of the inherited genes, just like regular brothers and sisters--but they don't have the added differences of age and environment which helps you tell apart regular brothers and sisters.

Whether or not fraternal twins look identical varies a lot from one pair to another. I even know some pairs of identical twins that look more different (because of different hair styles, body language, ways of dressing, etc.) than some pairs of fraternal twins. The fraternal twins who look most similar probably come from families where both parents are from similar ethnic backgrounds and have similar looking inherited facial features.

Part of it may also just be chance--some twins happen to inherit facial features or other features which make them appear very similar. In other families, the opposite may be true--I know many families where one sibling has wavy hair and another curly hair, with different hair colors and different skin tones.

Answer 6

actually fraternal twins are more like separately born siblings and the resemblance in each other is as much as seen the separately born sisters or brothers because genetically they have different genotypes which ultimately determines the external phenotypical appearance. this is because 2 different ova in the mother are fertilized by two different sperms.