Watching her mother cut off the ends of the roast before she placed it in the oven, year after year, the curious child finally asked why she cuts off the ends of a perfectly fine looking roast. The mother replied that growing up she watched her mother do this year after year. Now her curiosity was peaked – if her wise grandma did it, there must be a good reason. She decided to pick up the phone and quiz her grandma straightaway. Initially the grandma couldn’t recall why she had done this. After some thinking she recalled that the baking tray she used at the time was too small for the roast and she had to cut off the ends of so it would fit. The mother had just followed what the grandmother had done without understanding why.

Detecting relationships that do not exist:

Daniel Kahneman and Amos Tversky looked into the claim that people report arthritis pain when there’s a storm approaching. It turns out there’s no evidence for this whatsoever. Another one is emergency room nurses claim that there’s a lot more activity when there’s a full moon. Athletes routinely engaged in all sorts of superstitious types of beliefs, such as tying their shoes in a particular way, wearing their pair of lucky socks or shorts before a game or a competition. These beliefs are a result of seeing that two things that have happened together in the past: a pair of socks and their performance, or a full moon and the activity that took place that evening, but there is no link. There isn’t a link between them, but people see with certainty that there is a link. These superstitions are examples of what is called conformation bias, that is, we tend to notice things that confirm our beliefs and we don’t notice the things that contradict our beliefs.

According to Tom Gilovich of Cornell University, if we want to believe something, we will seek out evidence for the belief and we won’t seek out evidence against it. It’s a very pronounced tendency to treat information that’s consistent with what we want to believe in a pretty friendly way and be really hostile to information that’s inconsistent. It’s almost as if we ask ourselves: can I believe this, or is there evidence for this? There’s evidence for almost anything once you begin looking and ignoring inconsistent data. Even the most outlandish beliefs, there is some evidence for. The question is: is there sufficient evidence? Do we ask ourselves: must I believe this? Is there enough evidence here?  Or, is there data which calls this idea into question?

“Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense.” – the Buddha