Updated: Mar 2
We want to appear definitive in our beliefs. We want to exude confidence when arguing for and defending our points of view. We fear it will be seen as a sign of weakness if we are indecisive or change our minds – if we flip-flop.
Thomas Bayes, an 18th-century statistician, introduced the concept of conditional probability and what ultimately became known as Bayes' Theorem. His theorem has been generalized to a real-life mindset: Bayesian thinking. Knowing how we got from Bayes mathematical work to Bayesian thinking is not as important as concept itself – to properly understand our world, we must allow new information to challenge and marginally alter our previously held beliefs.
You have watched Jocko Slugger play baseball many times and believe that he is a great hitter. But the next time you see him bat, he strikes out. Does that mean that you should now think he is a horrible hitter? Of course not. Should it challenge your belief that he is still a great hitter? Well yes, it should, just a little bit. One strikeout is not enough to reverse your previously held beliefs about his skill because those beliefs are based on a much broader body of evidence, but the most recent evidence suggests that you shouldn't believe them now quite as strongly as you previously did. What if Jocko strikes out next time, and the next time, and the time after that? At some point, you are forced to believe that Jocko is no longer a great hitter. You flip-flop on your opinion of him, but you are using proper Bayesian thinking to reach that conclusion.
Research provides us new information which we should use to challenge our previously held beliefs. Sometimes that new information will align with our beliefs and make them even stronger. Other times it refutes them and gives us pause. Depending on the strength of our previous convictions and the forcefulness of the new evidence, we may even change our mind – we may flip-flop. But that’s ok – we have learned. We have used Bayesian thinking to reach a new belief. We are now more knowledgeable about the matter than we were before and it’s perfectly fine to not only admit that but to defend it. After all, remember - the Earth used to be flat.