History of the Term Regression

The term regression was first coined by Francis Galton in his article "Regression towards mediocrity in hereditary stature" . Galton worked on the following problem: it was known then that tall people have tall children and short people have short children. A preliminary conclusion of this would be that the variance of height should increase over time. Since this did not occur, Galton investigated the phenomenon and found that  height "regresses" towards the mean of the population. Thus tall people have tall children but somewhat shorter than themselves, and short people have short children but somewhat taller than themselves.

Galton found that the height of the children depends on the height of both the father and the mother, and that variance in the height of the population is reduced by the "regression" towards the mean by just enough to keep it almost constant over time.