“We have biases because our brain-design dates back to the stone age. Our intuitive decision-making consists of shortcuts, heuristics, that led to successful gene-copying more often than not in our ancestral environment. If you had a true belief that differed from the cherished beliefs of your group, you were at risk of ostracism. Our belief-acquiring mechanisms were not selected for producing accurate beliefs, but for producing beliefs that paid rent in terms of reproductive success. Upon reflection, we would hopefully come up with different personal goals. This mismatch between the (metaphorical) goals of our genes and our personal (very real) goals is one reason for the existence of cognitive biases.”

— Lukas Gloor, Rationality: The science of winning, Part III (Raising for Effective Giving)