In the past four decades, behavioral economists and cognitive psychologists have discovered many cognitive biases human brains fall prey to when thinking and deciding. Cognitive biases are tendencies to think in certain ways that can lead to systematic deviations from a standard of rationality or good judgment. These biases arise from errors of memory, social attribution, and miscalculations such as statistical errors or a false sense of probability. Some social psychologists believe our cognitive biases help us process information more efficiently, especially in dangerous situations. Still, they lead us to make grave mistakes. We may be prone to such errors in judgment, but at least we can be aware of them.
Bayesian reasoning offers a way to improve on the native human reasoning style. Reasoning naively, we tend not to seek alternative explanations, and sometimes underrate the influence of prior probabilities in Bayes' theorem.
Credits: Wikipedia, LessWrong.org