I wish Simone had not made the observation.Brown people, she told me, drive old cars. I looked at Ken with a raised eyebrow. He was not surprised because Simone had told him about her observation a few weeks earlier. When he relayed her message to me, I thought about one of my biggest fears -- that some day Simone will identify herself as white and cast aside her black heritage. Our observant 4-year-old takes good notes. Old cars are square; new cars are round. She has peered into cars and noticed most of the older ones are driven by brown people. She has made no mention about who drives the newer cars. As her brown mother, I drive an old car, or at least it is older than her father's car. His car is about a year old. When we purchased it, we decided he would drive it. His commute is much shorter than mine, and we wanted to put all of the miles on my then 3-year-old car. Besides, I love my car and all her dings and dents. Simone, meanwhile, has noticed her father's car has a few features my car does not have, and she has asked why. My response: His car is newer; my car is older. I should note that Simone describes me as brown, her father as beige, and herself as tan. Until now, I have followed a long-held theory. Young children don't understand the complexities of race; prejudice is learned. What we as parents should do -- regardless of the race of our children -- is expose them to children of different races, ethnicities, religions and socio-economic backgrounds, and then let nature take its course. Now after observing my own child and reading more than a few articles about the matter, I'm not so sure that is the best approach. A recent Newsweek magazine article speaks directly to what we have noticed in Simone. She has been making lists and trying to make sense of them. That's what kids do; that's how they learn. We teach them their colors, their numbers, their shapes. We teach them to make distinctions. So, why wouldn't they make distinctions about themselves and others? The article is an excerpt of "NurtureShock" by Po Bronson and Ashley Merryman. It turns out Simone is not out of the ordinary. Children as young as 6-months-old judge others based on the color of their skin. Even when researchers have found willing participants to discuss race, many of them didn't follow through and dropped out of the research. A quick summary on how we think about race and children has changed: Then: We assumed children didn't notice race until we pointed out to them. Now: Evidence shows children identify racial differences much like they see the differences between pink and baby blue -- two colors often used to distinguish girls from boys. Then: Like me, many parents figured children would get the diversity point after we exposed them to different races and cultures. Now: Researchers have found the more diverse the environment, the more likely children self-segregate. Then: Parents kept quiet about race even when children discussed it. Now: Conversations with children about race should be explicit and put in terms children understand. Then: Children often told about discrimination were less likely to see the relationship between working hard and achieving goals. Now: Black children who repeatedly hear messages of black pride are more interested in school and more likely to connect their success to their hard work and persistence. What are parents of a biracial children to do? I have decided to teach more, a lot more. Sure, I told Simone it may appear to her that brown people only drive older cars but that plenty of them drive new cars. I also know we will be discussing why in the not-to-distant future. I have tried to stay out of the way when it comes to race, let Simone come to some of her own conclusions. I am learning, though, she is going to force Ken and me to talk about race more than we previously thought, or had planned. In our case, we can't simply drop out of the study because it uncomfortable for us to confront the issues. Four years down, a lifetime to go. To be continued.