Karl Pearson: Statistician, Scientist, and Divisive Thinker

Karl Pearson is one of those historical figures who sparks both admiration and deep controversy. He was a pioneer in mathematical statistics, laying down the foundations for many of the statistical techniques we still use today. But he was also a strong advocate for eugenics and social Darwinism, beliefs that have left a much…

John C. Raven: The Psychologist Who Reshaped IQ Testing

John Carlyle Raven (1902–1970) wasn’t just another psychologist—he was a game-changer in the world of intelligence testing. His name might not be as instantly recognizable as Freud or Pavlov, but if you’ve ever taken a nonverbal IQ test, especially one that involves patterns and logic, you’ve seen his influence firsthand. Raven’s Progressive Matrices (RPM)…

Robert Yerkes: Psychology, Primates, and a Dark Legacy

Robert Mearns Yerkes was one of those names that had a massive impact on psychology, but not always for the right reasons. Born in 1876 and passing in 1956, he left behind a complicated legacy—one filled with groundbreaking work in intelligence testing, pioneering research in primatology, and, unfortunately, a strong connection to the eugenics…