Regression to the mean
Sep 6, 2018 · 2 min read
Regression to the mean is one of the most misunderstood and widely used concepts in statistics.
It’s easy to show that it’s widely used. A Google search showed 2.5 million hits. Google ngram viewer shows that it first appeared in 1913 but has climbed steadily and is now about as common as “eat your words”.
But what is it?
The phrase was originated by Francis Galton in the late 19th century. Galton noticed that extremely tall parents tended to have children who are taller than average, but not as tall as they are. Similar things happen with…

