A weapon....................................

       In psychology there are at least two biases that drive this pattern.  One is confirmation bias:  seeing what we expect to see.  The other is desirability bias:  seeing what we want to see.  These biases don't just prevent us from applying our intelligence.  They can actually contort our intelligence into a weapon against the truth.  We find reasons to preach our faith more deeply, prosecute our case more passionately, and ride the tidal wave of our political party.  The tragedy is that we're usually unaware of the resulting flaws in our thinking.

        My favorite bias is the "I'm not biased" bias, in which people believer they're more objective that others.  It turns out that smart people are more likely to fall into this trap. The brighter you are, the harder it can be to see your own limitations.  Being good at thinking can make you worse at rethinking.

-Adam Grant,  Think Again:  The Power of Knowing What You Don't Know