Natural variation and decision making

Imagine you are in your 9th grade. You scored 80%, everyone expected you to. The teacher praises you. Your friend scored 40% and the teacher scolds him. Next exam. You score 76%. Your friend gets 45%. What just happened? It is seemingly logical that praising you got you to slack off and lose your grade while your friend benefited after scolding. The thing is, while it appears that the teacher influenced the grades, such a fluctuation is likely to be a natural fluctuation. Plain and simple changes that depend on so many variables that they appear random to us. There is a very high chance that the teacher's scolding and praising changed nothing. This is called the regression fallacy . It is based on a couple of things. One is to discount natural variation. These innocuous random and natural fluctuations are often underestimated. Two, erroneous attribution of events to a controllable cause. Natural variations and fluctuations are significant causes that we often underestimate Where w...