So who’s right? Are conservatives more prejudiced than liberals, or vice versa? Research over the years has shown that in industrialized nations, social conservatives and religious fundamentalists possess psychological traits, such as the valuing of conformity and the desire for certainty, that tend to predispose people toward prejudice. Meanwhile, liberals and the nonreligious tend to be more open to new experiences, a trait associated with lower prejudice. So one might expect that, whatever each group’s own ideology, conservatives and Christians should be inherently more discriminatory on the whole.There's much more on this at the link, and much more about liberal and conservative attitudes that you might find surprising. One minor quibble I had with the article was that I didn't see anything that indicated how the researchers or the article's writers defined either prejudice or intolerance. For example, it's not made particularly clear whether intolerance is defined as simply disagreeing with the other side or actually trying to shut the other side up.
But more recent psychological research, some of it presented in January at the annual meeting of the Society of Personality and Social Psychology (SPSP), shows that it’s not so simple. These findings confirm that conservatives, liberals, the religious and the nonreligious are each prejudiced against those with opposing views. But surprisingly, each group is about equally prejudiced. While liberals might like to think of themselves as more open-minded, they are no more tolerant of people unlike them than their conservative counterparts are.
If it's the former then "prejudice" is unexceptional and anodyne. If, however, it's the latter then it's relevant to note that two places where prejudice is today manifesting itself as sheer intolerance of heterodox opinions is in the media and on university campuses. It may be that were these institutions dominated by conservatives they would be just as intolerant and narrow-minded as they are under liberals, but we have no way of knowing.
We do know, though, that in the contemporary world these institutions are dominated largely by liberals who flatter themselves to think that they are paragons of tolerance when in fact they're often as eager to punish deviations from liberal orthodoxy as was any medieval inquisitor. Indeed, totalitarian thought-control has always been, at least since the onset of modernity, a temptation and phenomenon of the left.