Joseph Jastrow (1863 - 1944)

Joseph Jastrow (January 30, 1863 – January 8, 1944) was an American psychologist, noted for inventions in experimental psychology, design of experiments, and psycho-physics. Jastrow was one of the first scientists to study the evolution of language, publishing an article on the topic in 1886. He also worked on the phenomena of optical illusions, and a number of well-known optical illusions (such as the Jastrow illusion) were either discovered or popularized in his work.