Powerful pull of belief

In general, these types of belief systems are coherent and logically consistent when you are inside them. It is not until you step outside the group and gain a different reference point that the coherence and logic vanishes. This is why cults control the movements of their members, and especially their access to outside information and contact with friends and loved ones in the real world. (Jones moved his group to Guyana from San Francisco.) There also are well-known social psychological effects at work in these groups -- such as the loss of individuality and the compliance of behavior and conformity of thought under group pressure, along with the diffusion of individual responsibility and group think.

But there is something deeper going on here that I think touches on cognitive processes in all of us as members of non-cult groups, such as political parties: confirmation bias. This is when we look for and find evidence to support what we already believe, and ignore or rationalize away evidence that does not. And because we are so tribal by nature, we employ confirmation bias with extra vigor when it comes to defending the groups we belong to. Republicans tend to listen to conservative talk radio, watch Fox News and read the Wall Street Journal, gathering data and noting arguments that support their political beliefs. Democrats are more likely to listen to progressive talk radio and NPR, surf liberal blogs and read the New York Times. Everyone does it.

Confirmation bias explains why so many rumors about candidates were eagerly embraced recently. On the left, commentators glommed onto false gossip about Sarah Palin's ignorance (she doesn't know that Africa is a continent) and bigotry (she tried to ban books from the public library) because liberals think that conservatives are dumb and dogmatic, and after eight years of George W. Bush's malapropisms and Palin's interview fumbles, such rumors merely confirmed what liberals already believed.

On the right, conservatives were primed to process hearsay about Barack Obama being a Muslim or Arab as true, or that his tax plan -- indistinguishable from that of most Democratic candidates in recent decades -- confirmed that he's a socialist, even while Republicans were nationalizing the financial industry and running up record debts.