I think that communism was a major force for violence for more than 100 years, because it was built into its ideology - that progress comes through class struggle, often violent.

Like the early days of the Internet, the dawn of personal genomics promises benefits and pitfalls that no one can foresee.

Words let us say the things we want to say and also things we would be better off not having said. They let us know the things we need to know, and also things we wish we didn't.

Knowing there is a world that will outlive you, there are people whose well-being depends on how you live your life, affects the way you live your life, whether or not you directly experience those effects. You want to be the kind of person who has the larger view, who takes other people's interests into account, who's dedicated to the principles that you can justify, like justice, knowledge, truth, beauty and morality.

One of the things that people complain about is loneliness, disconnectedness. If you live in a society where your life is rarely threatened and most of your relationships are more on an economic exchange basis, then this could leave people feeling less connected.

But the 20th century suffered "two" ideologies that led to genocides. The other one, Marxism, had no use for race, didn't believe in genes and denied that human nature was a meaningful concept. Clearly, it's not an emphasis on genes or evolution that is dangerous. It's the desire to remake humanity by coercive means (eugenics or social engineering) and the belief that humanity advances through a struggle in which superior groups (race or classes) triumph over inferior ones.

The reason I'm not a neurobiologist but a cognitive psychologist is that I think looking at brain tissue is often the wrong level of analysis. You have to look at a higher level of organization.