The Trap of Generalizing Negatively from a Single Number

Before you read this latest blog, please first take a look at Richard Erdmann’s Youtube video on Factfulness below. Then read his expanded thoughts in this blog!

The book, Factfulness, attempts to address the issue of limited success by looking at mental traps. Mental traps are created in part because the brain tends to look for the easier explanation – the path of least resistance. Looking at the complexity of an issue requires work and the brain does not mind avoiding work. This explains two of the mental traps we will explore. The willingness to work from a single number or incident, the first mental trap, and to generalize from insufficient information, the second mental trap. The brain is also drawn to the negative, the third mental trap. It is drawn to an explanation that creates an emotional response and the negative does this more readily than the positive. Perhaps this is because historically the brain had to be overly sensitive to threat. If the threat is not clear but is possible, assume the worst and get out of there.

Some 20 years ago the media made a generalization from a single number and portrayed American public education as failing. The trends of average SAT scores in reading and math were declining year after year. The media’s generalization from this fact was that American education was in a steady state of decline and that we needed a remedy for this pending disaster. The fact was right but the conclusion was the result of these three mental traps in combination and totally wrong.

Let’s start with the size or single number problem. There is something called Simpson’s Paradox in statistics. It says that you can have a trend, in this case an improving trend, in all of several subgroups of a population and when the groups are averaged, the trend disappears and can even be reversed. For a variety of reasons more and more students in the US were choosing to go to college for either an associates or four year degree – a good thing. When they first began showing up to take the SAT test, they lowered the average score because these were not our best high school graduates in terms of academics. In another time they would not have chosen college. More and more of these students showed up every year and the trend of these students was improvement. Every year, every subgroup, Hispanics, African Americans, Native Americans, whites, Asians, males and females, was getting better scores but the average of them combined went down because the lowest achieving of these groups represented a bigger and bigger percentage of the total test taking population every year. The American public thought that public education was getting worse when it was, in fact, getting better. Then the media, who probably knew better, chose to appeal to the readers by using the negative rather than the positive because, unfortunately, the negative gathers more attention than the positive. What the media could have headlined instead was the following: All Subgroups in the US are Improving on the SAT Tests: American Public Education has Never Been Better.

The point of Factfulness is that we have to expect people to think and neither the brain nor the media is always on our side in this. Therefore we need to teach and adopt coping strategies. The book is building tools for reasoning to compensate for a often uncooperative brain.

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