“We’re at our worst when it comes to politics,” declares Paul Bloom in an essay about reason and morality:

Most of us know nothing about constitutional law, so it’s hardly surprising that we take sides in the Obamacare debate the way we root for the Red Sox or the Yankees. Loyalty to the team is what matters. A set of experiments run by the Stanford psychologist Geoffrey Cohen illustrates this principle perfectly.

Subjects were told about a proposed welfare program, which was described as being endorsed by either Republicans or Democrats, and were asked whether they approved of it. Some subjects were told about an extremely generous program, others about an extremely stingy program, but this made little difference. What mattered was party: Democrats approved of the Democratic program, and Republicans, the Republican program. When asked to justify their decision, however, participants insisted that party considerations were irrelevant; they felt they were responding to the program’s objective merits. This appears to be the norm.

The Brown psychologist Steven Sloman and his colleagues have found that when people are called upon to justify their political positions, even those that they feel strongly about, many are unable to point to specifics. For instance, many people who claim to believe deeply in cap and trade or a flat tax have little idea what these policies actually mean.

So, yes, if you want to see people at their worst, press them on the details of those complex political issues that correspond to political identity and that cleave the country almost perfectly in half.

Recent Dish on Bloom’s work here.