One of the first things our pediatrician said when she met us and our fraternal twin boys, was, Don't compare them. She came out strong with that. She looked me in the eye and said, Don't compare them. I was surprised how firm she was.

I nodded and agreed. I couldn't see how comparing the boys would do either of them very good. "Look how smart your brother is! Can't you be more like him?" How monstrous. We would not do that.

But as they have gotten older, the comparisons just... start... creeping in. One boy is active and explores everywhere. His brother sits quietly and studies details. One boys likes sensory thrills, like swinging in a baby swing. His brother furrows his brow in concern and waits for the swinging to be over. One overheats easily, the other shivers.

We can't help it. We see these differences and they are fascinating. When you procreate, you watch the kid, with all his quirks and personality and you think, When we make babies, this is how they turn out. But then you have another baby, that kid is very likely to be different.

Natural, right? Of course your kids would all be different. Because you are different. There has been a passage of time. Maybe you've moved. Maybe you have a new job. You've grown as your kids grow. You learn things. Also, you are older. So it's not a surprise that kids of different ages will have distinctions between them.

With our fraternal twins, they are as genetically similar as siblings born five years apart. They look different. They have unique personalities. They both have blue eyes, but different blue eyes. One guy has dark cobalt blue eyes, wide and soulful. The other has eyes that are lighter, more gray, and twinkly. One is remarkably patient as Mama picks his boogers. The other fights strenuously. We are watching them grow up at the same time, in the exact same environment. So when we observe how different they are, we realize we are lucky winners in a random genetic lottery.

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Our boys just turned one year old. We can't help but compare them. We see them developing at different rates, sometimes leapfrogging each other, reaching milestones in their own sweet time. When we think we have them pegged, they change or switch roles. The one that used to be more reserved is now a natural comedian. The one who used to smile all the time is now a little more discerning. We are endlessly intrigued as we watch them grow.

We already see hints that one boy will be shy, like his Papa, and the other will be outgoing like his Mama. I can say with certainty that crabbiness in hot weather definitely comes from me. One guy is totally unfazed by hot weather, like his Papa. The other guy's face flushes like a little tomato. And he whines unhappily. Oh, the whining. I hear ya, kid.

Of course, the whining comes from his dad.