This list is a follow up to Top 10 Common Faults in Human Thought. Thanks for everyone’s comments and feedback; you have inspired this second list! It is amazing that with all these biases, people are able to actually have a rational thought every now and then. There is no end to the mistakes we make when we process information, so here are 10 more common errors to be aware of.

The confirmation bias is the tendency to look for or interpret information in a way that confirms beliefs. Individuals reinforce their ideas and attitudes by selectively collecting evidence or retrieving biased memories. For example, I think that there are more emergency room admissions on nights where there is a full moon. I notice on the next full moon that there are 78 ER admissions, this confirms my belief and I fail to look at admission rates for the rest of the month. The obvious problem with this bias is that that it allows inaccurate information to be held as true. Going back to the above example, suppose that on average, daily ER admissions are 90. My interpretation that 78 are more than normal is wrong, yet I fail to notice, or even consider it. This error is very common, and it can have risky consequences when decisions are based on false information.