Black-and-white thinking, uncolored by the reality of uncertainty, is a driver of both motivated reasoning and self-serving bias. If our only options are being 100% right or 100% wrong, with nothing in between, then information that potentially contradicts a belief requires a total downgrade, from right all the way to wrong. There is no “somewhat less sure” option in an all-or-nothing world, so we ignore or discredit the information to hold steadfast in our belief.
