4

They May Not Look and Act Alike

Monozygotic twins are called "identical" because they often have remarkably similar appearances and characteristics. This stems from the fact that they share the same genetic makeup (or genotype), although their DNA is not necessarily identical.﻿﻿

Fraternal twins, on the other hand, are as alike as any two siblings. They may look very different. They can have different hair color, eye color, stature, and personalities. Or, they may indeed be so similar that they are assumed to be identical, just as some siblings would be remarkably indistinguishable, if only they were the same age.

Twins and multiples are also shaped by their environment after they are born.﻿﻿ Some similarities are enhanced because they are raised in the same home, share the same experiences, and are educated in the same schools at the same time.