Joseph Jastrow

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Lore & Background

Jastrow was born in Warsaw, Poland, a son of Talmud scholar Marcus Jastrow and the younger brother of orientalist Morris Jastrow, Jr. He came to Philadelphia in 1866 and received his bachelor's and master's degrees from the University of Pennsylvania. During his doctoral studies at Johns Hopkins University, Jastrow worked with C. S. Peirce on experiments in psychophysics that introduced randomization and blinding for a repeated measures design. Though Peirce had to leave the university due to a personal scandal, Jastrow continued to advance his own research. From 1888 until his retirement in 1927, Jastrow was a professor at the University of Wisconsin–Madison, where he advised Clark L. Hull. He was a lecturer at the New School of Social Research from 1927 to 1933. Jastrow was head of the psychological section of the World's Columbian Exposition in 1893, where he collected 'psychophysical and reaction time data' from thousands of attendees. He was one of the charter members of the American Psychological Association, and became its president in 1900. He gave public lectures and was published in popular magazines including Popular Science, Cosmopolitan, and Harper's Monthly. He also wrote 'Keeping Mentally Fit,' a syndicated column that appeared in 150 newspapers, and gave radio talks from 1935 to 1938 through the Philadelphia Public Ledger Syndicate. Jastrow was a founding member of the American Society for Psychical Research but resigned by 1890, becoming an outspoken critic of parapsychology. In his book 'The Psychology of Conviction' (1918) he included an entire chapter exposing what he called Eusapia Palladino's tricks. His book 'Fact and Fable in Psychology' (1900) debunked claims of occultism including Spiritualism, Theosophy and Christian Science. He viewed paranormal phenomena as 'totally unscientific and misleading,' being the result of delusion, fraud, gullibility and irrationality.

Reader's Guide

Jastrow's significance comes from his work in anomalistic psychology and his public outreach. He approached the occult in a scientific manner, wanting to understand why people were attracted to it, how it gained a foothold in society, and what evidence its supporters used. He wrote that many people considered coincidence, dreams, and premonitions as sources of information above science, and said the role of the scientist was to help the public understand truth from fiction. He studied the psychology of paranormal belief and debunked claims throughout his career. Beyond debunking, Jastrow contributed to experimental psychology through his work with Peirce on randomized and blinded experiments. He invented a machine called the automagraph to detect unconscious movement of the hand. He studied dreams of the blind, finding that people who lost eyesight after age six still saw in dreams, while those who lost it before age five could not. He also criticized psychoanalysis as unscientific and pseudoscience as early as 1913, later publishing 'The House that Freud Built' in 1932. His work on optical illusions, including the rabbit–duck illusion, illustrated his belief that mental processing of images was central to interpretation of the world.

Did You Know?

• Jastrow worked with C. S. Peirce on psychophysics experiments that introduced randomization and blinding for a repeated measures design.
• He was head of the psychological section of the World's Columbian Exposition in 1893, collecting data from thousands of attendees.
• His syndicated column 'Keeping Mentally Fit' appeared in 150 newspapers.
• Jastrow invented a machine called the automagraph to detect unconscious movement of the hand.
• He criticized psychoanalysis as unscientific and pseudoscience as early as 1913, later publishing 'The House that Freud Built' in 1932.