The Republican Brain by is Mooney Page A

and associations that are called into the conscious mind based on a network of emotionally laden associations and concepts. “They retrieve thoughts that are consistent with their previous beliefs,” says Taber, “and that will lead them to construct or build an argument and challenge to what they are hearing.”
    In other words, when we think we’re reasoning we may instead be rationalizing. Or to use another analogy offered by University of Virginia social psychologist Jonathan Haidt: We may think we’re being scientists, but we’re actually being lawyers. Our “reasoning” is a means to a predetermined end—winning our “case”—and is shot through with classic biases of the sort that render Condorcet’s vision deeply problematic. These include the notorious “confirmation bias,” in which we give greater heed to evidence and arguments that bolster our beliefs, and seek out information to reinforce our prior commitments; as well as its evil twin the “disconfirmation bias,” in which we expend disproportionate energy trying to debunk or refute views and arguments that we find uncongenial, responding very defensively to threatening information and trying to pick it apart.
    That may seem like a lot of jargon, but we all understand these mechanisms when it comes to interpersonal relationships. Charles Dickens understood them, even if not by name. If I don’t want to believe that my spouse is being unfaithful, or that my child is a bully—or, as in Great Expectations, that a convict is my benefactor—I can go to great lengths to explain away details and behaviors that seem obvious to everybody else. Everybody who isn’t too emotionally invested to accept them, anyway.
    That’s not to suggest that we aren’t also motivated to perceive the world accurately—we often are. Or that we never change our minds—we do. It’s just that we sometimes have other important goals besides accuracy—including identity affirmation and protecting our sense of self. These can make us highly resistant to changing our beliefs when, by all rights, we probably should.

    Since it is fundamentally rooted in our brains, it should come as no surprise that motivated reasoning emerges when we’re very young. Some of the seeds appear to be present at least by age four or five, when kids are able to perceive differences in the “trustworthiness” of information sources.
    â€œWhen 5-year-olds hear about a competition whose outcome was unclear,” write Yale psychologists Paul Bloom and Deena Skolnick Weisberg, “they are more likely to believe a person who claimed that he had lost the race (a statement that goes against his self interest) than a person who claimed that he had won the race (a statement that goes with his self-interest).” For Bloom and Weisberg, this is the very capacity that, while admirable in general, can in the right context set the stage for resistance to certain types of information or points of view.
    The reason is that where there is conflicting opinion, children will decide upon the “trustworthiness” of the source—and they may well, in a contested case, decide that Mommy and Daddy are trustworthy, and the teacher talking about evolution isn’t. This will likely occur for emotional, motivated, or self-serving reasons.
    As children develop into adolescents, motivated reasoning also develops. This, too, has been studied, and one of the experiments is memorable enough to describe in some detail.
    Psychologist Paul Klaczynski of the University of Northern Colorado wanted to learn how well adolescents are capable of reasoning on topics they care deeply about. So he decided to see how they evaluated arguments about whether a kind of music they liked (either heavy metal or country) led people to engage in harmful or antisocial behavior (drug abuse, suicide, etc.). You might call it the