In statistics, Galton was the first to describe and explain the common phenomenon of regression toward the mean in the 1870s and 1880s. After examining forearm and height measurements, Galton introduced the concept of correlation in 1888. His statistical study of the probability of extinction of surnames led to the concept of Galton-Watson stochastic processes.
The method of identifying criminals by their fingerprints had been introduced in the 1870s by William Herschel. In 1892, 1893 and 1895 Galton wrote three books about the technique, identifying common pattern in fingerprints and devising a classification system that survives to this day. He also estimated the probability of two persons having the same fingerprint and studied the heritability and racial differences in fingerprints.
Galton invented the Quincunx, also known as the bean machine as a tool for demonstrating the law of error and the normal distribution.
Galton was knighted in 1909, and died in Haslemere, Surrey.