Humans have evolved over time to avoid discomfort, so when we encounter issues that we disagree with it’s much easier to simply ignore them or classify them as being wrong without putting too much thought, effort or reasoning into it. An alarm bell usually goes off in our head alerting us to this inconsistency, so we give ourselves a mental break to avoid these internal conflicts.
From Meir Statman’s book 'What Investors Really Want'
"We want high returns from our investments, but we want much more. We want to nurture hope for riches and banish fear of poverty. We want to be number 1 and beat the market. We want to feel pride when our investments bring gains and avoid regret that comes with losses. We want the status and esteem of hedge funds, the warm glow and virtue of socially responsible funds, and the patriotism of investing in our own country. We want good advice from financial advisors, magazines, and the Internet. We want financial markets to be fair but search for an edge that would let us win, sometimes fair and at other times not. We want to leave a legacy for our children when we are gone. And we want to leave nothing for the tax man. The sum of our wants and behaviours make financial markets go up or down as we herd together or go our separate ways, sometimes inflating bubbles and other times popping them."