What most people are inadvertently expressing is, "I am surprised that they have two different personalities." To educate someone on the reason that question can be a little annoying (instead of being snarky), I need to think about the reason behind the question. I try to imagine what is like to not be around identical twins all the time and to only know the science behind twins, but not the hearts of the twins.
Or maybe you've grown up hearing stories (or seen movies) of identical twins who know when the other is wounded from 1,000 of miles away. I can then see the added mystery and confusion. Yes they are physically and spiritually linked, just as you and your siblings are connected. I will never be able to fully understand the spiritual connection between family, yet I know God intended for there to be an extra bond in heritage. And identical twins have a special bond I will never truly understand. But I urge you (smiling and not mad) to think of the implication you unconsciously make when you assume their DNA means they are the same person. Identical twins share DNA, not a soul.
Yes, identical twins are an egg split in half, but they are not a soul split in half. I believe our God is sovereign and powerful enough to create two identical bodies with two different souls. He knit their hearts and minds together in my womb, each of them...separately. One twin is not an accident or afterthought once the first one was knit. He knew them both separately and uniquely gifted them with their own talents, souls, and spiritual gifts. Very similarly to the fact that he took you and your spouse's DNA and miraculously made different combinations of different people in your children.
I am no scientist, and I may be wrong in how I view this, but I have lived for six and half years with two boys who technically are suppose to be the "same person'" according to their DNA. Yet from the moment of their conception they were different and unique. If you get me going I can tell you many stories of their differences, like how my ever moving kinesthetic learner Batman never stopped moving in my stomach. Or how Spider-man latched the first nursing session and ate quickly, but Batman was the slowest nursing baby he face of the planet (he still likes to take his time in everything he does). They are not the exactly the same or exact opposites. They are uniquely themselves. They are each who God knit them to be.
So after all this I guess I need to amend my earlier snarky response. Yes, it is amazing that they have two different personalities, because the God who made them is Amazing.
To see more questions and answers about Twins, see the blog post: