His family has roots in early Massachusetts Bay Colony with ancestors that included Thomas Brigham (1603–1653)[2] and Edmund Rice (1594–1663).

[5][6] At the outbreak of World War I, Brigham joined the military and was commissioned as first lieutenant in the Sanitary Corps, psychological service from October to December 1917 at Camp Dix.

[5] After the war was over, Brigham joined Princeton as a faculty member in 1920 and began working on adapting the army mental tests for use in college admissions.

Harvard Professor E.G. Boring suggested that Brigham was not collecting data with scientific purpose which biased his results in favor of his ideas (1923).

[7] College Board reviewed his book, A Study of American Intelligence, and wanted a test that could be administered to a wider group of schools that was developed by Brigham.

There was no evidence in Brigham's study suggesting that intelligence, as reflected in the test scores, was related to social success or achievements.

"[8][9] He realized that the SAT test scores do not measure innate ability passed through genes, but are instead a "composite including schooling, family background, familiarity with English, and everything else relevant and irrelevant" (Fussell, 2019).