THINKING 101, Lesson 9: Hasty Generalizations

When we reason, or infer, lots of things can go wrong. Some of the simplest (and most common) reasoning errors are just when we try to do it too quickly.

Any time we reason, we are using a "body of evidence" that we collected from our own life experience, or from other people who shared their experience. If our "body of evidence" is too small, we can easily arrive at the wrong conclusion.

Example: "Bill lied to me. Janet lied to me. Everyone lies to me!"

In the science of statistical analysis, when the sample of data is small, conclusions are unreliable. When the sample size drops to one, the reliability of any conclusion is zero.

Also, if our "body of evidence" is not well-enough related to the idea in question, we can arrive at a useless conclusion.

Example: "Lettuce is green. Spinach is green. Broccoli is green. Cabbage is green. If I run out of food, I can eat green paper!"

In this example, the person was close, but not close enough. "Green" often implies "plant," and plants are often (but not always) edible. Unfortunately for our hungry person, other things are green too.

Bon appétit !