- (1856–1939) An Austrian neurologist and pioneer in the field of psychoanalysis. Freud’s comprehensive
theory of psychoanalysis sought to explain the structure of the human mind, human attitudes and behavior, mental disorders, and
the origins of civilization. Freud’s ideas, particularly his emphasis on sexuality, were highly controversial in the repressive Victorian
era in which he lived. He published a revolutionary book called
The Interpretation of Dreams
in 1900 and a more concise version
of his theories called
in 1903. His ideas have had an enormous influence on Western thought, but they continue to be
Galton, Sir Francis
- (1822–1911) A British scholar who advocated eugenics, the study of human improvement through
selective breeding. Galton was interested in the idea that intelligence is inherited. He believed that intelligence is related to
sensory ability and attempted to assess intelligence by measuring sensory abilities such as sensitivity to sound, color perception,
and reaction time. Although he failed to correlate intelligence with these sensory abilities, his work paved the way for subsequent
research on assessing mental abilities.
Helmholtz, Hermann von
- (1821–1894) The inventor of the ophthalmoscope, an instrument for examining the eye. Von
Helmholtz lent further support to Young’s theories of color. He also developed a sophisticated theory of harmony.
- (1849–1936) A doctor best known for his research on the conditioned reflex. Pavlov made his most famous
discovery while studying how dog saliva related to the function of the stomach. He found that when he repeatedly gave a dog food
after ringing a bell, the dog began to salivate for false alarms too. The bell rang, and the dog salivated, even with no food in sight.
Pavlov won a Nobel Prize for his work in 1904.
Skinner, B. F.
- (1904–1990) A psychologist who built on Pavlov’s work to develop theories of operant behavior. Skinner wrote
The Behavior of Organisms
in 1938, in which he described his work on operant behavior. He wrote several other books as well,
including a popular though controversial novel,
. Skinner studied operant conditioning by using the Skinner box.
- (1874–1949) The psychologist who formulated the law of effect, among other theories of learning.
Thorndike primarily focused on animal behavior.
- (1878–1958) The founder of a school of psychology known as behaviorism. Watson studied the effects of