LASHLEY, KARL SPENCER

(b. Davis, West Virginia, 7 June 1890; d. Poitiers, France, 7 August 1958),

psychology, neurophysiology. For the original article on Lashley see DSB, vol. 8.

A major biographical treatment of Karl Lashley since the original DSB article is Nadine Weidman’s Constructing Scientific Psychology: Karl Lashley’s Mind-Brain Debates (1999). Weidman’s interpretation builds on earlier biographical work on Lashley by Darryl Bruce and Donald Dewsbury but also differs from it in noteworthy ways. Bruce has written two biographical articles on Lashley. One of them, “Lashley’s Shift from Bacteriology to Neuropsychology,

1910–1917, and the Influence of Jennings, Watson, and Franz” (1986), is focused on Lashley’s early career and traces the path that took him from bacteriology and genetics to his life’s work in neuropsychology. The other, “Integrations of Lashley” (1991), is a portrayal of Lashley as a pioneering psychologist. Dewsbury has examined a correspondence between Lashley and Lashley’s mentor and friend from the 1950s, John B. Watson, late in both men’s lives, in “Contributions to the History of Psychology XCIV: The Boys of Summer at the End of Summer” (1993).

While Bruce and Dewsbury portray Lashley as a pure, disinterested scientist whose work was devoid of social or political meaning, Weidman argues that Lashley’s neutral stance and avowed opposition to psychological theorizing were themselves political statements and that Lashley’s concept of brain function and his lifelong hereditarianism were correlated with his views on race and on the social order. Weidman’s biography emphasizes Lashley’s hereditarianism—his belief that intelligence and brain function were innate properties rather than influenced strongly by environment—and uses that emphasis to explain Lashley’s scientific stance, his opposition to certain traditions in psychology and biology, and his sociopolitical leanings.

According to this interpretation, Lashley’s doctoral work in genetics, done under the supervision of the biologist Herbert Spencer Jennings, encouraged Lashley’s interest in uncovering the biological and genetic bases of behavior. Lashley allied himself with the behaviorist Watson up to the mid-1920s, but he broke with behaviorism just as Watson was asserting the total shaping power of the environment on behavior. Lashley’s mature work involved the ablation, or destruction, of different areas of the rat’s cerebral cortex and the assessment of its effect on the rat’s behavior. He devised ingenious methods for testing the rats’ abilities to thread a maze, solve a puzzle box, and discriminate between different patterns, before and after ablation. The principles of equipotentiality and mass action that Lashley derived from his experimental work emphasized the dynamic functioning of the cortex and were opposed to the theory that memories, thoughts, or abilities were localized in discrete cells. This experimental work received thorough treatment in Brain Mechanisms and Intelligence (1929), the only book Lashley ever wrote. Lashley’s emphasis on dynamic functioning was also, according to Weidman, correlated with his innatist stance.

Lashley’s hereditarianism and interest in elucidating the biological bases of behavior brought him into conflict with two important traditions in twentieth-century American biology and psychology. His career was shaped by his debates with representatives of these two traditions, psychobiology and behaviorism. The first conflict pitted Lashley against his colleague at the University of Chicago, the psychobiologist and neurologist Charles Judson Her-rick. For Herrick, consciousness and free will were emergent properties of the nervous system that could never be fully explained by physics and chemistry. Lashley dismissed Herrick’s emergentism as mystical, arguing for the reduction of consciousness to the physico-chemical workings of the nervous system and against the notion of progress in evolution that underlay Herrick’s theory. Sharon Kingsland explores the assumptions of Herrick’s science in “A Humanistic Science: Charles Judson Herrick and the Struggle for Psychobiology at the University of Chicago” (1993). In Constructing Scientific Psychology (1999), Weidman develops Lashley’s side of the debate and examines his interactions with Herrick.

The second major debate of Lashley’s career was with Clark Hull, the neo-behaviorist psychologist at Yale University’s Institute of Human Relations in New Haven, Connecticut. In Hull, Lashley faced an opponent who was quite as opposed to Herrick’s emergentism as was Lashley himself. Both Hull and Lashley claimed the mantle of mechanistic, deterministic psychology but disagreed on what that meant. For Hull, behavior was the product of reflex connections between stimulus and response; how these connections were actually achieved in the brain mattered to him less than that behavioral outputs could be manipulated by changing the stimulating sensory inputs. Hull also believed that intelligent behavior could be simulated by a machine and spent some effort designing and building such “thinking machines.” According to Weidman, Lashley objected to such mechanical analogies for the mind and to Hull’s neo-behaviorist theory as well as to the emphasis on the environmental shaping of behavior that underlay Hull’s science.

Weidman’s interpretation of the Lashley-Hull debate in her book expands on her earlier article, “Mental Testing and Machine Intelligence: The Lashley-Hull Debate” (1994). Bruce criticizes Weidman’s interpretation of the debate in this article in “The Lashley-Hull Debate Revisited” (1998). Weidman’s response to Bruce (“A Response to Bruce”) and Bruce’s reply (“Lashley’s Rejection of Connectionism”)—in which he argues that a change in evidence from Lashley’s experiments underlay his break from behaviorism—can both be found in the May 1998 issue of History of Psychology.

Dewsbury compares Bruce’s and Weidman’s views of Lashley in his article “Constructing Representations of Karl Spencer Lashley.” There Dewsbury argues, in a critique of Weidman, that Lashley’s theories of dynamic cortical function and his emphasis on innate ability could be interpreted as correlated with his idiosyncratic and iconoclastic personality rather than with his sociopolitical views. Dewsbury’s article, Weidman’s response to it (“The Depoliticization of Karl Lashley”), and Dewsbury’s reply to her (“The Role of Evidence”) can all be found in the summer 2002 issue of the Journal of the History of the Behavioral Sciences.

Lashley ended his career as the director of the Yerkes Laboratories of Primate Biology in Orange Park, Florida. In keeping with his career-long interests, Lashley guided the work of the laboratories toward an investigation of the biological and ultimately genetic basis of intelligence and of sexual behavior in anthropoid apes.

SUPPLEMENTARY BIBLIOGRAPHY

Bruce, Darryl. “Lashley’s Shift from Bacteriology to Neuropsychology, 1910–1917, and the Influence of Jennings, Watson, and Franz.” Journal of the History of the Behavioral Sciences 22 (1986): 27–44.

———. “Integrations of Lashley.” In Portraits of Pioneers in Psychology, Vol. 1, edited by Gregory A. Kimble, Michael Wertheimer, and Charlotte White. Hillsdale, NJ: Erlbaum, 1991.

———. “The Lashley-Hull Debate Revisited.” History of Psychology 1, no. 1 (February 1998): 69–84.

———. “Lashley’s Rejection of Connectionism.” History of Psychology 1, no. 2 (May 1998): 160–164.

Dewsbury, Donald A. “Contributions to the History of Psychology XCIV: The Boys of Summer at the End of Summer: The Watson-Lashley Correspondence of the 1950s.” Psychological Reports 72 (1993): 263–269.

———. “Constructing Representations of Karl Spencer Lashley.” Journal of the History of the Behavioral Sciences 38, no. 3 (Summer 2002): 225–245.

———. “The Role of Evidence in Interpretations of the Scientific Work of Karl Lashley.” Journal of the History of the Behavioral Sciences 38, no. 3 (Summer 2002): 255–257.

———. Monkey Farm: A History of the Yerkes Laboratories of Primate Biology, Orange Park, Florida, 1930–1965. Lewisburg, PA: Bucknell University Press, 2006.

Kingsland, Sharon. “A Humanistic Science: Charles JudsonHerrick and the Struggle for Psychobiology at the University of Chicago.” Perspectives on Science 1 (1993): 445–477.

Weidman, Nadine M. “Mental Testing and Machine Intelligence: The Lashley-Hull Debate.” Journal of the History of the Behavioral Sciences 30 (April 1994): 162–180.

———. “Psychobiology, Progressivism, and the Anti-Progressive Tradition.” Journal of the History of Biology 29 (1996): 267–308.

———. “A Response to Bruce (1998) on the Lashley-Hull Debate.” History of Psychology 1, no. 2 (May 1998): 156–159.

———. Constructing Scientific Psychology: Karl Lashley’s Mind-Brain Debates. New York; Cambridge, UK: Cambridge University Press, 1999.

———. “The Depoliticization of Karl Lashley: A Response to Dewsbury.” Journal of the History of the Behavioral Sciences 38, no. 3 (Summer 2002): 247–253.

Nadine M. Weidman

Lashley, Karl Spencer

(b Davis, West Virginia, 7 June 1890; d. Poitiers, France 7 August 1958),

psychology, neurophysiology.

Karl Lashley’s ancestry was English, primarily middle class. His father, Charles Gilpin Lashley, was a merchant in Davis, West Virginia, and its mayor and postmaster for many years. Lashley contended that he had received his native endowment from his mother, Maggie Blanche Spencer, a descendant of Jonathan Edwards. She exerted a profound influence upon her only child, encouraging his intellectual pursuits with her own library of 2,000 volumes. As a boy Karl collected various animal and plant specimens on long walks in the country. Throughout his life he formed assorted collections and kept unusual pets.

After receiving his B.A. from West Virginia University in 1910 he was awarded a teaching fellowship in biology at the University of Pittsburgh. He received his Ph.D. in 1914 from Johns Hopkins University under Jennings and Mast. In 1917 Lashley was instructor of psychology at the University of Minnesota; by 1923 he had been promoted to full professor. He remained at Minnesota until 1926, when he joined the staff at the University of Chicago as research psychologist; and he became professor of psychology in 1929. From 1935 to 1955 he was research professor of neuropsychology at Harvard University and, from 1942, director of the Yerkes Laboratories of Primate Biology.

In 1918 Lashley married Edith Ann Baker, an accomplished musician who died in 1948. A son born in 1919 died shortly thereafter. In 1957 he married Claire Imredy Schiller, widow of the Hungarian psychologist Paul Schiller.

Lashley was one of the world’s foremost physiological psychologists. His scientific activities may be divided into four distinct periods. In the first (1912-1918) he laid a firm foundation in animal behavior working with lower forms, including their genetic make-up. In the second (1919-1929) his most noted contributions related to his penetrating analysis of the rat brain, in particular cerebral localization and interneuronal connections. His ideas of the learning process emerged from this analysis, culminating in Brain Mechanisms and Intelligence (New York, 1964). His theory of the equipotentiality of the cortex attracted world-wide attention and his article “In Search of the Engram” (The Neuropsychology of Lashley, pp. 478-505) made him famous. In the third period (1930-1942) he concerned himself primarily with vision, the chief sensory modality in learning. Few other scientific endeavors have equaled this thorough study of vision in relation to learning. In the final period (1941-1958) Lashley was a theorizer, especially on learning. He was also the world’s sharpest critic of other theories, and especially of his own. He wrote: “My bricks won’t hang together without speculative straw that I know is hooey.”

BIBLIOGRAPHY

See Frank A. Beach’s memoir of Karl Lashley in Bio-graphical Memoirs. National Academy of Sciences, 35 (1961), 163-196. A full and complete bibliography of Lashley’s works follows on pp. 196-204. The Neuro-psychology of Lashle, F. A. Beach, D. O. Hebb, C. T. Morgan, and H. W. Nissen, eds. (New York, 1960), is a collection of Lashley’s major publications.

Paul G. Roofe

Karl Spencer Lashley

1890-1958
American neuropsychologist who demonstrated relationships between animal behavior and the size and location of brain injuries, summarizing his findings in terms of the concepts of equipotentiality and mass action.

Karl Spencer Lashley was born at Davis, West Virginia, on June 7, 1890. Even as a child he was interested in animals, an interest which continued throughout his adult life. His mother, Maggie Lashley, encouraged him in intellectual pursuits. After studying at the University of West Virginia and then taking a master's degree in bacteriology at the University of Pittsburgh, Lashley did doctoral and postdoctoral research at Johns Hopkins University. While at Hopkins, he was influenced by the zoologist H. S. Jennings, the psychiatrist Adolf Meyer , and the psychologist John B. Watson, the father of behaviorism .

Lashley was at once an experimental researcher and a psychological theoretician. His investigations were published in the leading journals and proceedings of major scientific societies. After several joint studies with Jennings, Lashley published his own thesis, "Inheritance in the Asexual Reproduction of Hydra." He collaborated with Watson in studying behavior in seabirds, acknowledging Watson's behavioristic approach the rest of his life.

Collaborating with Shepherd Ivory Franz, Lashley produced several papers on the effects of cerebral destruction upon retention and habit formation in rats. This was the beginning of his preoccupation with one of the persistent problems in psychology, that of cerebral localization. Earlier researchers Gall, Broca, Fritsch and Hitzig, Ferrier, and Munk were all believers in exact

cerebral localization, whereas Flourens, Goltz, and Franz doubted it. The culmination of his localization experiments was Brain Mechanisms and Intelligence: A Quantitative Study of Injuries to the Brain (1929), his longest, most significant monograph. In it he summarized his concepts of equipotentiality and mass action and marshaled the experimental evidence to support them. Thus he accounted for the absence of precise and persistent localization of function in the cortex. Lashley's experiments denied the simple similarity and correspondence, previously assumed, between associationistic connectionism and the neuronal theory of the brain as a mass of neurons connected by synapses.

In addition to his researches Lashley taught as professor of psychology at the universities of Minnesota and Chicago and at Harvard University. He held various honorary positions and lectureships, was on the editorial boards of numerous scientific journals, served as member of and adviser to governmental committees, and was elected to many scientific and philosophical societies. He died on August 7, 1958, in Poitiers, France.

Further Reading

Beach, Frank A. Karl Spencer Lashley. 1961.

Beach, Frank A., ed. The neuropsychology of Lashley. 1960.

Karl Spencer Lashley

The American neuropsychologist Karl Spencer Lashley (1890-1958) demonstrated relationships between animal behavior and the size and location of brain injuries, summarizing his findings in terms of the concepts of equipotentiality and mass action.

Karl Spencer Lashley was born at Davis, W. Va., on June 7, 1890. Even as a child he was interested in animals, an interest which continued throughout his adult life. His mother, Maggie Lashley, encouraged him in intellectual pursuits. After studying at the University of West Virginia and then taking a master's degree in bacteriology at the University of Pittsburgh, Lashley did doctoral and postdoctoral research at Johns Hopkins University. While at Hopkins, he was influenced by the zoologist H. S. Jennings, the psychiatrist Adolf Meyer, and the psychologist John B. Watson, the father of behaviorism.

Lashley was at once an experimental researcher and a psychological theoretician. His investigations were published in the leading journals and proceedings of major scientific societies. After several joint studies with Jennings, Lashley published his own thesis, "Inheritance in the Asexual Reproduction of Hydra. …" He collaborated with Watson in studying behavior in seabirds, acknowledging Watson's behavioristic approach the rest of his life.

Collaborating with Shepherd Ivory Franz, Lashley produced several papers on the effects of cerebral destruction upon retention and habit formation in rats. This was the beginning of his preoccupation with one of the persistent problems in psychology, that of cerebral localization. Earlier researchers Gall, Broca, Fritsch and Hitzig, Ferrier, and Munk were all believers in exact cerebral localization, whereas Flourens, Goltz, and Franz doubted it. The culmination of his localization experiments was Brain Mechanisms and Intelligence: A Quantitative Study of Injuries to the Brain (1929), his longest, most significant monograph. In it he summarized his concepts of equipotentiality and mass action and marshaled the experimental evidence to support them. Thus he accounted for the absence of precise and persistent localization of function in the cortex. Lashley's experiments denied the simple similarity and correspondence, previously assumed, between associationistic connectionism and the neuronal theory of the brain as a mass of neurons connected by synapses.

In addition to his researches Lashley taught as professor of psychology at the universities of Minnesota and Chicago and at Harvard University. He held various honorary positions and lectureships, was on the editorial boards of numerous scientific journals, served as member of and adviser to governmental committees, and was elected to many scientific and philosophical societies. He died on Aug. 7, 1958, in Poitiers, France.

Further Reading

An enjoyable biographical narrative of Lashley's life and work by Frank A. Beach, Karl Spencer Lashley (1961), includes a chronological bibliography of his writings. Lashley's contributions to psychological literature are representatively sampled in a collection, The Neuropsychology of Lashley, edited by Frank A. Beach (1960), which includes as an introduction a penetrating evaluation by Edwin G. Boring, as well as an appreciation by the neurologist Stanley Cobb. □