In a column for Newsweek magazine, science writer Sharon Begley* discusses how ignorance about the statistical principle of regression to the mean** causes all sorts of crazy behavior. For example, sufferers of colds try a new remedy that seems to make them better, but in reality, they were already recovering. This behavior leads to over-use of antibiotics, which breeds drug-resistant bacteria. Ultimately, according to this quote passed along by Begley:
“People die at a biblical scale because of such stupidity.”
– Ben Goldacre, author of Bad, Science: Quacks, Hacks and Big Pharma Flacks.
On a lighter (?) note, this tendency by people to attribute cause-and-effect relationships to random ups-and-downs explains why some teachers, coaches and instructors hold back praise and only berate their pupils. A case in point is the flight instructor who lavishes praise on a training-pilot who makes a lucky landing. Naturally the next result is not so good. Later the pilot bounces in very badly — again purely by chance (a gust of wind). The instructor roars disapproval. That seems to do the trick — the next landing is much smoother. So now you know why coaches yell so much: It’s their regression to the mean.
* “Wanted: BS Detectors” – 11/8/10.
**First brought forward by France Galton in 1886 via this essay on “Regression towards Mediocrity in Hereditary Stature”