When choosing a sperm donor, my partner and I pored over the profiles, trying to figure out what traits we'd most want our children to have. I'm guessing that most straight couples don't get together based on optimal genetics but when you can choose 50% of your kids' genes from a catalog it can be surprisingly overwhelming. In terms of physical appearance, we chose a donor who might resemble my partner — brown eyes, black hair, and olive skin — but there were personality traits to consider as well. Did we want the free-spirited dancer with a great sense of humor or the extroverted political science major who loved sports and music? In the end, we chose the extroverted political science major because, if there was to be any genetic influence on personality, we didn't want our kids to be shy like us and because my partner loves sports and I love music.

We are now 14 years into this parenting gig. I don't know how much genetics contributes to our kids' talents and personalities. Or how much is a result of how we have raised them.

We have a video of our son at 6 months old, crawling through the house at high speed and batting a soccer ball ahead as he goes. At 2 years old, I sat in the park and watched him on the basketball court as he tried to shoot his tiny basketball into the full-sized hoop. He was so small and the hoop was so high but he tried over and over again without stopping and, after nearly an hour, he finally made one. Over the years, he tried tee-ball, hockey, water skiing, snowboarding, gymnastics and even surfing before finally settling on soccer. I didn't play sports as a kid. I'm the person most likely to trip and fall bringing groceries into the house. So we can safely assume his athletic ability does not come from me.

He started high-school soccer practice last week, which makes me reflect on the passage of time but, more than that, I'm marveling at the fact that my son is going to be a high-school athlete. In the caste system of high school, he will be a jock and, though it's been a long time since I was in high school, I remember the jocks being quite different than me. Yes, I went to pep rallies and games and even had a letter jacket. But I lettered in Debate. That's right — I was a total nerd.

There are challenges to raising a child with a dramatically different personality than yours. As introverted parents, we have sometimes wished our extroverted children could be just a little less talkative and a little happier with a good book. But there also are gifts from such an experience. I've watched in awe as our son has executed a perfect bicycle kick and been impressed as our daughter brings home the Presidential Fitness Award year after year. When I compliment them on these accomplishments, they say, "I'm sure you could do it when you were my age," and I tell them, "No, I couldn't." Because of our differences, they can assert themselves as individuals and I have been able to see a version of childhood that is very different than my own.

And now, this nerd is preparing to see high school in an entirely different light as well. I'm guessing there will be pep rallies and games and a letter jacket, but that letter will have a soccer ball rather than a gavel.

PHOTO CREDIT: VIKKI REICH