A major one is how we tend estimate probability. We naturally do that by equating it with how easy it is to imagine or remember it happening. This worked well in a tribal situation where our world was very small...if Grog got attacked by a tiger, there's a good chance that tiger attacks are a serious danger that I should consider. But this breaks down in the face of a global society of billions of people and a media that profits from making people afraid. Rare events get magnified by media attention and feel, to us, like they're incredibly likely. Plane crashes are incredibly rare. Even in a plane as fundamentally broken as the 737 Max was, passengers were safer traveling that way than by car. But since every airplane crash is covered extensively on the news whereas car crashes rarely merit a mention, people's primitive cognitive quirks kick in and they're more afraid of flying. You see it with mass shootings too. Even if you get 1-2 per day in the US, that's still maybe a few hundred people per day who are directly affected. Over the course of a year, that's roughly 70k people out of 330 million, or %0.02 of the population. Which isn't to say that we shouldn't do everything we can to prevent it, but when you hear people saying that they don't feel safe, that's entirely on the media and how it's warping our perception of the danger rather than it being a real threat to our lives. We also saw it with the spate of Asian attacks that became a media favorite. There was a story of Asians in New York starting to contort their lives to avoid becoming victims. But when I looked up the actual statistics, there were 20 such attacks at the time in a city with 1.2 million Asians. Which, again, doesn't mean that we shouldn't be treating each of those attacks as terrible and be doing everything we can to stop them, but when you consider 20 victims out of 1.2 million, that's just not a risk that's worth going to considerable inconvenience to avoid.
There was an interesting TED talk many years ago from a guy who specialized in these kinds of cognitive quirks. And he discussed the findings of one particular study that always stuck with me. In it, participants were presented with one of two hypothetical situations. In the first, they were going to the theater to see a movie and they pre-purchased the ticket for $20, and also brought along a $20 bill. When they arrived at the theater, they found that the ticket had gone missing. Almost all participants in the study said they'd turn around and go home rather than using the other $20 to purchase another ticket. In the second case, they were going to the theater to see the same movie, but instead of having pre-purchased a ticket, they were intending to buy one when they got there. But they had, instead, brought two $20 bills with them and managed to lose one on their way to the theater. Almost all participants presented with this scenario chose to use their remaining $20 bill to buy a ticket. Despite the situation being basically identical, when you're presented with both scenarios, we have a cognitive quirk where we don't want to pay for something twice whereas we can rationalize the loss of money that we never spent. But what got to me about that study wasn't the results, but how intuitive both decisions felt to me. I could feel how unpleasant it would be to buy a second ticket and, yet, how easy a decision it would be to buy a ticket for the first time even after losing some of my money. The lesson, for me, was that while I've always thought of myself as a logical person and someone who would always let statistics or other scientific basis guide my thinking, it's still really hard to follow through with that.