We also need to maintain a healthy respect for diversity, Bowden says. It’s a principle that has gotten our human genome through some tough times and is essential in any evolving system. Bowden uses the example of a city, with a wide variety of businesses, some of which may succeed and grow in a given year while others may fail. A city with many different types of companies will be better equipped to survive financially if hard times arrive. If we all rush to give our kids the traits we think are best, we may end up being suckered in by fleeting cultural norms, and losing out on useful diversity. We should tread softly on issues like eliminating deafness, for instance, where a culture and language has developed.