Collectively we are not very effective at critical thinking. For starters, we immediately jump to conclusions, the default reaction to new information. Daniel Kahneman explains this in his essential book Thinking, Fast and Slow. If the subject is not clear cut, take a bit of time to think more about it.
Most people don’t have a good grasp of probability; it is something scientists are specifically trained for. We think of “N,” the number of replications. An event happens, N = 1, and there is zero confidence in predicting future results. If the same event happens three times in a row, people automatically think “cause and effect.” That’s not good enough. When we do experiments, we try for at least 25 replications, and that only gives us around 95% confidence in the results; one time in 20 we will still be wrong. So the next time something unusual happens to you, think “N = 1” and be patient.
If the event is truly impressive or frightening we tend to give it more importance. Every time a plane goes down, we all shudder and wonder about the safety of flying. But your probability of dying in bulk commercial aircraft is one in seven million. You are 19 times more likely to die stepping into a car.
And perhaps the best example of skewed understanding of probabilities is nuclear power. Chernobyl, the result of clearly shoddy improper procedures, resulted in about sixty total deaths attributed to immediate blast effects, half of those occurring well after the event. Because dosages were so low, there is a lot of debate over possible subsequent cancer deaths, with no resolution possible because the radiation levels were so low that accurate damage prediction is impossible.
Fukushima also scared a lot of people, although there were no immediate radiation-caused deaths. Several dozen people died from evacuation stress-related events. Fifteen thousand died as a result of the earthquake and tsunami. Nuclear waste bothers a lot of people, although if you got your entire lifetime of electricity from nuclear power, the waste would be the size of a door knob (usually stored in pools of water on site at the moment). Nuclear has by far the lowest death rate of nonrenewable sources, and that is almost entirely due to mining accidents. It has prevented millions of pollution-related deaths and its footprint is far smaller than solar, wind, or hydroelectric.
But what about critical thinking in daily events? We all read the news in various formats and much of what we browse is either exaggerated or untrue. How to know? First, consider the source. A reputable news medium counts for a lot; if you get all your information from Fox (as my brother does), at best you’re getting shoddy information. Look at the source. Ideally it’s a publication from a reputable scientific or medical journal, or maybe from a doctor or scientist. If you’re doubtful, follow the money. It’s a climate denial from a person funded by Exxon? Ha. And if it’s completely undocumented and a conspiracy theory to boot, stop reading.
I still find it incredible that any rational person would believe Qanon… but then, they aren’t rational, are they?