Robert Choate Tryon (September 4, 1901 – September 27, 1967) was an American

behavioral psychologist Behaviorism is a systematic approach to understanding the behavior of humans and animals. It assumes that behavior is either a reflex evoked by the pairing of certain antecedent stimuli in the environment, or a consequence of that individual ...

, who pioneered the study of

hereditary Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...

trait inheritance and learning in animals. His series of experiments with laboratory rats showed that animals can be selectively bred for greater aptitude at certain

intelligence tests An intelligence quotient (IQ) is a total score derived from a set of standardized tests or subtests designed to assess human intelligence. The abbreviation "IQ" was coined by the psychologist William Stern for the German term ''Intelligenzqu ...

, but that this selective breeding does not increase the

general intelligence The ''g'' factor (also known as general intelligence, general mental ability or general intelligence factor) is a construct developed in psychometric investigations of cognitive abilities and human intelligence. It is a variable that summarizes ...

of the animals.

Life

Tryon was born in Butte, Montana on September 4, 1901. He spent most of his life at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

. He received his AB degree from the undergraduate school in 1924, and as a graduate student he earned his Ph.D. in 1928 with thesis titled ''Individual differences at successive stages of learning''. After graduating from the school he spent two years as a National Research Council fellow. In 1931, he became a faculty member of the college's Department of Psychology, of which he was a member for 31 years. During the War he served in Washington DC as the deputy chief of the planning staff for the Office of Strategic Services. Aside from that short period, he was always in Berkeley. On September 27, 1967, he died in

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emer ...

."University of California: In Memoriam, May 1969." Content.cdlib.org. Web. 14 Dec. 2010. .

Work

In the 1940s, influenced by the studies of his former professor

Edward C. Tolman Edward Chace Tolman (April 14, 1886 – November 19, 1959) was an American psychologist and a professor of psychology at the University of California, Berkeley. Through Tolman's theories and works, he founded what is now a branch of psychology know ...

, Tryon decided to test the theory that intelligence is an inherited trait. To do this, he tested the ability of laboratory rats to navigate a maze: rats who took fewer wrong turns to get through the maze and reach the food at the end were termed "maze-bright", while those who took many wrong turns were termed "maze-dull". Tryon then interbred the maze-bright rats with other maze-brights, and maze-dull rats with other maze-dulls. With each successive generation, the ability to navigate the maze increased in the brights and decreased in the dulls. Known as

Tryon's Rat Experiment Tryon's Rat Experiment is a psychology experiment conducted by Robert Tryon in 1940 and published in the ''Yearbook of the National Society for Studies in Education.'' Experiment set-up Prior to Robert Tryon’s study of selective rat breeding, ...

, this study was highly influential in the field of psychology for showing that specific behavioral traits may be hereditary. Tryon was also a pioneer in the use of

cluster analysis Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters). It is a main task of ...

to analyze data. His 1939 monogram ''Cluster Analysis'' was one of the first works to outline a cluster analysis method, and he continued to develop this method over the course of his career.

References

{{DEFAULTSORT:Tryon, Robert People from Butte, Montana 20th-century American psychologists University of California, Berkeley alumni 1901 births 1967 deaths