Editing Psychometrics (section)

=== Victorian stream ===
Charles Darwin was the inspiration behind Francis Galton, a scientist who advanced the development of psychometrics. In 1859, Darwin published his book ''[[On the Origin of Species]]''. Darwin described the role of natural selection in the emergence, over time, of different populations of species of plants and animals. The book showed how individual members of a [[species]] differ among themselves and how they possess characteristics that are more or less adaptive to their environment. Those with more adaptive characteristics are more likely to survive to procreate and give rise to another generation. Those with less adaptive characteristics are less likely. These ideas stimulated Galton's interest in the study of human beings and how they differ one from another and how to measure those differences.

Galton wrote a book entitled ''[[Hereditary Genius]]'' which was first published in 1869. The book described different characteristics that people possess and how those characteristics make some more "fit" than others. Today these differences, such as sensory and motor functioning (reaction time, visual acuity, and physical strength), are important domains of scientific psychology. Much of the early theoretical and applied work in psychometrics was undertaken in an attempt to measure [[intelligence (trait)|intelligence]]. Galton often referred to as "the father of psychometrics," devised and included mental tests among his [[anthropometric]] measures. [[James McKeen Cattell]], a pioneer in the field of psychometrics, went on to extend Galton's work. Cattell coined the term ''mental test'', and is responsible for research and knowledge that ultimately led to the development of modern tests.<ref name = "kap">Kaplan, R.M., & Saccuzzo, D.P. (2010). ''Psychological testing: Principles, applications, and issues'' (8th ed.). Belmont, CA: Wadsworth, Cengage Learning.</ref>