The Republican Brain by is Mooney Page B

Tipper Gore versus Frank Zappa experiment, recalling the 1980s debate over whether rock lyrics were corrupting kids and whether some albums needed to have parental labels on them.
    Ninth and twelfth graders were presented with arguments about the behavioral consequences of listening to heavy metal or country music—each of which contained a classic logical fallacy, such as a hasty generalization or tu quoque (a diversion). The students were then asked how valid the arguments were, to discuss their strengths and weaknesses, and to describe how they might design experiments or tests to falsify the arguments they had heard.
    Sure enough, the students were found to reason in a more biased way to defend the kind of music they liked. Country fans rated pro-country arguments as stronger than anti-country arguments (though all the arguments contained fallacies), flagged more problems or fallacies in anti-country arguments than in pro-country ones, and proposed better evidence-based tests of anti-country arguments than for the arguments that stroked their egos. Heavy metal fans did the same.
    Consider, for example, one adolescent country fan’s response when asked how to disprove the self-serving view that listening to country music leads one to have better social skills. Instead of proposing a proper test (for example, examining antisocial behavior in country music listeners) the student instead relied on what Klaczynski called “pseudo-evidence”—making up a circuitous rationale so as to preserve a prior belief:
    As I see it, country music has, like, themes to it about how to treat your neighbor. So, if you found someone who was listening to country, but that wasn’t a very nice person, I’d think you’d want to look at something else going on in his life. Like, what’s his parents like? You know, when you’ve got parents who treat you poorly or who don’t give you any respect, this happens a lot when you’re a teenager, then you’re not going to be a model citizen yourself.
    Clearly, this is no test of the argument that country music listening improves your social skills. So the student was pressed on the matter—asked how this would constitute an adequate experiment or test. The response:
    Well . . . you don’t really have to, what you have to look for is other stuff that’s happening. Talk to the person and see what they think is going on. So you could find a case where a person listens to country music, but doesn’t have many friends or get along very well. But, then, you talk to the person and see for yourself that the person’s life is probably pretty messed up.
    Obviously this student was not ready or willing to subject his or her beliefs to a true challenge. “Adolescents protect their theories with a diverse battery of cognitive defenses designed to repel attacks on their positions,” wrote Klaczynski.
    In another study—this time, one that presented students with the idea that their religious beliefs might lead to bad outcomes—Klaczynski and a colleague found a similar result. “At least by late adolescence,” he wrote, “individuals possess many of the competencies necessary for objective information processing but use these skills selectively.”

    The theory of motivated reasoning does not, in and of itself, explain why we might be driven to interpret information in a biased way, so as to protect and defend our preexisting convictions. Obviously, there will be a great variety of motivations, ranging from passionate love to financial greed.
    What’s more, the motivations needn’t be purely selfish. Even though motivated reasoning is sometimes also referred to as “identity-protective cognition,” we don’t engage in this process to defend ourselves alone. Our identities are bound up with our social relationships and affiliations—with our families, communities, alma maters, teams, churches,