The Study of Nonhumans: Animal Psychology

Darwin’s theory of evolution had raised questions about the adaptive utility of consciousness; the relation of human to animal ancestry had raised issues of whether there are instincts in humans and whether animals exhibited human intellectual
capacities and consciousness in adapting to changed or changing environments. Learning capacities and consciousness seemed in turn to depend upon the complexity of the nervous system: “If there is a Comparative Anatomy there is also a Comparative Psychology” (Chadbourne, 1872). George J. Romanes (1848–1894), a devoted younger friend of the aging Darwin, explored these concerns by collecting anecdotes of wild and domestic animals that provided evidence of capacities for reasoning and problem solving analogous to those exhibited by humans. As part of an animal’s intelligent
adaptation to an environment, he sought evidence of reason, stimulus situation, without the mediation of ideas. The bond between response and situation was strengthened if the response was followed by a satisfying outcome, or weakened if it was followed by an unsatisfactory consequence. This statement constituted Thorndike’s “law of effect.” He also held that bonds between the situation and response became
strengthened through exercise and weakened by disuse: the “law of exercise” (Thorndike, 1913). Thorndike claimed that these two laws, together with the animal’s “readiness” to respond in the situation, accounted for most of animal learning
(Thorndike, 1913). In his early work in comparative psychology, Thorndike emphasized a discontinuity between animals and humans. By 1911, however, he reversed his position to emphasize instead the universality of the law of effect and other laws of learning (Bruce, 1997). Although the thrust of Thorndike’s laws was to specify
regular relations between a situation and the responses that it may come to evoke, without any attempt to assess the content of the mind of the responding animal, comparative psychology did not immediately follow his lead. Concerns for the
adaptive value of consciousness in humans and animals continued to be addressed in the early decades of the twentieth century (e.g., Judd, 1910). Identifying the levels of complexity of nervous systems that would justify inferences about the nature of animal consciousness and capacity for intelligent behavior (e.g., Yerkes, 1905) is best exemplified by what has sometimes been called the first textbook in comparative psychology, Margaret Washburn’s The Animal Mind (1908) (Jaynes, 1968, cited in Furumoto & Scarborough, 1987). Margaret Floy Washburn (1871–1939), the first woman to
earn a PhD in psychology and the second woman president of the American Psychological Association (1921), summarized and organized the scattered literature on animal psychology, provided a history of the movement, and offered an extensive discussion of methodology for research with animals (Washburn, 1908; Goodman, 1980). E. B. Titchener’s first doctoral student, Washburn had applied to study psychology with James McKeen Cattell at Columbia, but Columbia, like Harvard and the Johns Hopkins University, permitted women to attend classes only unofficially as “hearers.” Cattell, however, encouraged her to apply to Cornell, where she completed her degree in 1894. Areport of her Cornell dissertation on the effects of visual imagery on tactile sensitivity was one of the few studies published in Wundt’s Philosophische
Studien that had not been completed at Leipzig. Washburn sought to understand the animal’s conscious experience in an approach to comparative psychology characterized
as “subjective, inferential and rigorously logical” (Goodman, 1980, p. 75). Washburn was influenced by the research and writing of both Morgan and Thorndike; like
Thorndike, she advocated the use of objective and rigorous experimental procedures, but, like Morgan, she persisted in her view that animals possessed a consciousness that psychology was obliged to define and characterize (Washburn, 1917, 1926, 1936). To carry out its responsibility, psychology needed to adopt objective and rigorous experimental procedures. Despite the growing emphasis on the sufficiency of behavioral data and the emphatic rejection of mind and consciousness as the only legitimate subject matter for a scientific psychology, as Thorndike advocated, Washburn held to her position (Goodman, 1980). which he defined as the conscious knowledge of the relation of the means to an end. In addition, Romanes described
patterns of instinctive responses that occurred without a conscious awareness of the end to which they were adapted (Romanes, 1892). Romanes’ research methods and anthropomorphic conclusions about the capacities of animals were criticized by
C. Lloyd Morgan (1852–1936) for relying on unsubstantiated anecdotes and weak analogical reasoning. Morgan emphasized the importance of observation and encouraged parsimony in interpreting observations of animal behavior (Morgan, 1890–1891, 1896). His caution in this regard came to be known as Morgan’s Canon: “In no case should an animal’s activity be interpreted in terms of higher psychological processes if it could be interpreted in terms of processes standing lower in the scale of psychological evolution” (R. I. Watson & Evans, 1991, p. 329). Morgan provided a necessary methodological corrective to enthusiastic but unscientific fact gathering by emphasizing both care in making observations and caution in interpreting them.
Morgan employed experimental methods and observation in naturalistic settings and hypothesized that animals learned through association of ideas, in accord with the philosophical tradition of associationism (Warren, 1921) that described how the human mind operated (Cumming, 1999; Furumoto & Scarborough, 1987). Although we can know our own consciousness, we can only infer consciousness in others, including animals; for Morgan, the criterion for inferring consciousness in animals is “circumstantial evidence that the animal . . . profits by experience” (Morgan, 1900). In this way, Morgan stimulated interest in the study of learning, not only as an adaptation to the environment, but also as the criterion for inferring animal consciousness or mind.
At Clark, research in animal behavior attempted to describe the animal mind and to study the development of the nervous system. The former research was represented by Willard Small’s use of the maze to study the mental processes of the white rat involved in learning (Small, 1900, 1901). The latter research was represented by H. H. Donaldson, who attempted to describe the growth of the nervous system in rats and humans (e.g., Donaldson, 1908). One purpose of this research by Donaldson and Small was to relate the complexities of the nervous system between species and between individuals in the same species to differences in behavioral and mental abilities.
Small employed a version of the Hampton Court maze (Munn, 1950) that later gave rise to the many variations (e.g., the T-maze, multiple T-maze, and the straight alley maze) that became standard laboratory equipment for the study of learning and the testing of learning theories of the 1930s through the 1950s. Donaldson and Swiss American psychiatrist Adolf Meyer are credited with helping to establish the albino rat as the dominant laboratory animal in American psychological laboratories for many decades (Logan, 1999). The work at Clark proceeded in the spirit exemplified by
Morgan and by E. L. Thorndike (1874–1949), who, in 1898, had insisted that experiment must be substituted for observation and the collection of anecdotes” (Thorndike, 1898). Thorndike’s dissertation, Animal Intelligence (1898), signaled a major shift from a subjective, introspective, anecdotal study of animals to an objective, quantitative experimental approach with an emphasis on learning (Galef,
1998; Stam & Kalmanovitch, 1998). Thorndike’s emphasis on controlled observation was welcomed by Morgan, who advanced “the hope that comparative psychology has passed
from the anecdote stage to the higher plane of verifiable observation, and that it is rising to the dignity of science” (Morgan, 1898). Thorndike had pursued graduate study at Harvard with an investigation of the behavior of chickens, until the protests of his landlady forced him to move his chicken experiments to the basement of William James’s house (Dewsbury, 1998; Thorndike, 1936). Thorndike subsequently took his two “most educated chickens” to study the inheritance of acquired traits at Columbia University with James McKeen Cattell. The topic did not prove very fruitful, and Thorndike chose instead to examine the performance of cats and small dogs in puzzle boxes. The choice of puzzle boxes was influenced by the work of Romanes and Morgan, who had described dogs and cats learning to open garden gates through trial and error (Morgan, 1900). Thorndike’s boxes were designed to permit observation of animals’ attempts to escape from the box to reach food (Burnham, 1972). Various
boxes required manipulation of levers, pulling of loops, or combinations of responses to escape (Chance, 1999; Galef, 1998). Thorndike recorded and graphed the time taken to escape from the box as a function of the number of trials. He interpreted the gradual decline of the curve describing the time taken to escape from the box revealed by the graph to mean that learning proceeded gradually, through trial and
error. Responses that resulted in escape from the puzzle box appeared to be selected from random movements, in a manner analogous to the process of evolutionary selection. Thorndike insisted that responses were made directly to the stimulus situation, without the mediation of ideas. The bond between response and situation was strengthened if the response was followed by a satisfying outcome, or weakened
if it was followed by an unsatisfactory consequence. This statement constituted Thorndike’s “law of effect.” He also held that bonds between the situation and response became strengthened through exercise and weakened by disuse: the
“law of exercise” (Thorndike, 1913). Thorndike claimed that these two laws, together with the animal’s “readiness” to respond in the situation, accounted for most of animal learning (Thorndike, 1913). In his early work in comparative psychology, Thorndike emphasized a discontinuity between animals and humans. By 1911, however, he reversed his position to emphasize instead the universality of the law of effect and other laws of learning (Bruce, 1997). Although the thrust of Thorndike’s laws was to specify regular relations between a situation and the responses that it may come to evoke, without any attempt to assess the content of the mind of the responding animal, comparative psychology did not immediately follow his lead. Concerns for the
adaptive value of consciousness in humans and animals continued to be addressed in the early decades of the twentieth century (e.g., Judd, 1910). Identifying the levels of complexity of nervous systems that would justify inferences about the nature of animal consciousness and capacity for intelligent behavior (e.g., Yerkes, 1905) is best exemplified by what has sometimes been called the first textbook in comparative psychology, Margaret Washburn’s The Animal Mind (1908)(Jaynes, 1968, cited in Furumoto & Scarborough, 1987). Margaret Floy Washburn (1871–1939), the first woman to
earn a PhD in psychology and the second woman president of the American Psychological Association (1921), summarized and organized the scattered literature on animal psychology, provided a history of the movement, and offered an extensive discussion of methodology for research with animals (Washburn, 1908; Goodman, 1980). E. B. Titchener’s first doctoral student, Washburn had applied to study psychology with James McKeen Cattell at Columbia, but Columbia, like Harvard and the Johns Hopkins University, permitted women to attend classes only unofficially as “hearers.” Cattell, however, encouraged her to apply to Cornell, where she completed her degree in 1894. Areport of her Cornell dissertation on the effects of visual imagery on tactile sensitivity was one of the few studies published in Wundt’s Philosophische
Studien that had not been completed at Leipzig. Washburn sought to understand the animal’s conscious experience in an approach to comparative psychology characterized
as “subjective, inferential and rigorously logical” (Goodman, 1980, p. 75). Washburn was influenced by the research and writing of both Morgan and Thorndike; like Thorndike, she advocated the use of objective and rigorous experimental procedures, but, like Morgan, she persisted in her view that animals possessed a consciousness that psychology was obliged to define and characterize (Washburn, 1917, 1926, 1936). To carry out its responsibility, psychology needed to adopt objective and rigorous experimental procedures. Despite the growing emphasis on the sufficiency of
behavioral data and the emphatic rejection of mind and consciousness as the only legitimate subject matter for a scientific psychology, as Thorndike advocated, Washburn held to her position (Goodman, 1980).