Fooled Again and Again
Patterns are inevitable and we should not be surprised by them. Streaks, clusters, and correlations are the norm, not the exception. In a large number of coin flips, there are likely to be coincidental clusters of heads and tails. In nationwide data on cancer, crime, or test scores, there are likely to be flukey clusters. When the data are separated into smaller geographic units like cities, the most extreme results are likely to be found in the smallest cities. In athletic competitions between well-matched teams, the outcome of a small number of games is almost meaningless. Our challenge is to overcome our inherited inclination to think that all patterns are meaningful; for example, thinking that clustering in large data sets or differences among small data sets must be something real that needs to be explained. Often, it is just meaningless happenstance.