Groups become more extreme and entrenched in their beliefs and polarized from others when members only exchange information that reinforces their views and filter out all else or never learn of alternatives. Thus they narrow their options, and magnify each other's prejudices and misconceptions. This trend leads to blind spots in decision making and to extreme behavior, even terrorism.

The 'cash for clunkers' program was a big success in part because it gave people the sense that the economy was moving.

Great works - and I think Star Wars is a great work - are easily susceptible to multiple plausible interpretations. Some of them are pretty nutty, but the idea that we should see it as profoundly feminist, or as a deeply Christian tale, or as a Freudian exercise... I think all of those have some truth.

Even though Star Wars is easily read as feminist for its time - and even for now, with Princess Leia's role - people wouldn't make a movie like that in 2016, where the guys are mostly the tough ones, and the women aren't in positions of authority.

Rumors are nearly as old as human history, but with the rise of the Internet, they have become ubiquitous. In fact we are now awash in them. False rumors are especially troublesome; they impose real damage on individuals and institutions, and they often resist correction. They can threaten careers, policies, public officials, and sometimes even democracy itself.

I'm interested in how the Internet spreads information.

The sky is always falling or the sky is always bright. In some ways, this is really morning in America and we don't see it. People are living longer, the economy is doing pretty well. On the other hand, there are some ways of thinking in the current situation that make it look not so good, including our Star Wars prequels - like legislature, meaning they're talking a lot, not doing a lot.