Thinking fast and slow: One-step thinking

In the past few decades, psychologists and neuroscientists have learned a lot about how the brain works. The whole story isn't in, and won't be for a few decades (at least).  But enough is known to help us figure out that there are some dangers to standard rote learning. One of the best discussions of this is Daniel Kahneman's book, Thinking Fast and Slow. Kahneman identifies two primary modes of thinking: a fast mode, based on quick recall and the simplest story you can construct, and a slow more reflective mode.

As we saw in previous pages on models of memory and making meaning by association, evolution selects for mind and memory to be very much about survival and survival can be very much about understanding what's happening — right now! — quickly by making a link to something one remembers and fast.

This makes your fast thinking mode often the default mode, especially when you are under stress. Your fast mode can be quick and efficient, but it can also lead you astray. I call this one-step thinking. 

One step thinking is when you look at a situation or question and quickly, without any analytical thought, make a quick almost automatic response. "Oh! I recognize this and know the answer." It can be very dangerous and lead you astray, especially when you are beginning to learn a subject.

It's like moving your hands to catch a pillow thrown at you. You've had enough experience to know what to do without thinking about it. You certainly wouldn't want to analyze the motion using the principles of physics and doing a calculation! This pillow would drop (or hit you) long before you've complete your analysis.

One-step thinking of this type is very effective when you've built it up through developing expertise — through many years of experience, seeing it in many different situations.

But one-step thinking can be dramatically ineffective if you try to short circuit the learning process through rote memorization. The multiple repetitions that one does to learn by rote is not the same thing as developing expertise because it misses the developing of the understanding of context.

A great example of how one-step thinking can fail is if you are studying for a physics test and you memorize the answers of questions you have seen in class. On the test, the question might well look like one you have seen, but a subtle change in the conditions might result in a different answer being correct. Saying, "Oh! I know this one! Then answer is...." will lead you astray. This kind of thinking is particularly dangerous in multiple-choice tests. You might have gotten away with this kind of thinking in some introductory courses, but it's not a good way to deal with more advanced science learning.

A second, more dangerous example, is medical diagnosis. Sometimes, when doctors are pressed for time, they will look at a patient and focus on a symptom or two they see right away and say, "Oh! I know what this is! I'll just prescribe..." Now sometimes, if a doctor is a real expert, this can work because they are watching for signals that it might be something more. But way too often it can lead to a misdiagnosis and unfortunate results. (For an excellent discussion of these issues and LOTS of examples, see Jerome Goopman's, How Doctors Think.)

In this class we'll work to help you learn to think more about your thinking in order to avoid the kind of errors that one-step thinking can lead you into. In our Follow-ons to this page, we discuss a variety of "tools for knowing" that will be very helpful in learning how to add more sophisticated ways to build and check your knowledge than simple one-step thinking. As you become increasingly familiar with and comfortable with using these tools, you'll find them almost as quick — and a lot more reliable — than one-step thinking.

Joe Redish 7/3/11