'...each individual reasoner is really good at one thing: finding evidence to support the position she or he already holds, usually for intuitive reasons. We should not expect individuals to produce good, open-minded, truth-seeking reasoning, particularly when self-interest or reputational concerns are in play. But if you put individuals together in the right way, such that some of the individuals can use their reasoning powers to disconfirm the claims of others, and all individuals feel some common bond or shared fate that allows them to interact civilly, you can create a group that ends up producing good reasoning as an emergent property of the social system. This is why it's so important to have intellectual and ideological diversity within any group or institution whose goal is to find truth (such as an intelligence agency or community of scientists) or to produce good public policy (such as a legislature or advisory board).'
Jonathan Haidt, The Righteous Mind: Why Good People are Divided by Politics and Religion, p.105.
