Carpenter, C. R. (1905–1975)

During the 1930s, C. Ray Carpenter carried out the first modern studies of free-ranging primates. In its scope, duration, systematic data collection, and revelations about the naturalistic behavior of primates, his research went far beyond all previous studies, such as those by Bingham, Nissen, Zuckerman, and Marais. Although his 1931 doctoral dissertation was on the behavior of pigeons in captivity, he immediately switched to field research on free-ranging [Page 441]primates. Over the next decade, in Central America, Southeast Asia, and the Caribbean, he carried out landmark field studies of howler monkeys, spider monkeys, gibbons, and rhesus macaques. The rhesus were on Cayo Santiago, a small island off Puerto Rico, in a colony established in the late 1930s with monkeys that Carpenter shipped from India. In the years since then, that colony has been the subject of research by many scientists.

After completing his doctorate with Calvin Stone at Stanford (1931),Carpenter began his primate field studies under a 3-year postdoctoral appointment to Robert Yerkes's laboratory at Yale. Thereafter, he had professorial appointments in psychology at Columbia University (1934–1940) and in both psychology and anthropology, first at Pennsylvania State University (1940–1970), then at University of Georgia (1970–1975).

Although Carpenter was trained in psychology, his primate studies included a diversity of topics more characteristic of biology, including demography, manipulation and locomotion, foraging, ranging and territoriality, sexual behavior, mother-infant relationships, competition and cooperation, agonistic behavior, dominance relations, vocalization and communication, and grooming and play.

His field methods were essentially those of a descriptive naturalist, as he observed representative samples of populations on-site in their natural habitats and made accurate and detailed reports of his observations. He made several important contributions to the methodology of primate field studies, including (a) censusing groups as they progressed single file instead of when they were congregated; (b)breaking the complexity of ongoing interactions in a group into their more readily observed components, dyadic relationships; (c) gradually habituating animals to his presence and remaining at a distance at which he could observe them without undue disturbance; (d) taking advantage of available technology, including photography, sound recording, and playback equipment; (e) making objective records of behavior, often quantitative and checked when possible by repeated observation; and (f)taking representative samples, not just of the dramatic or unusual.

Carpenter was adamant about the potential of observational field studies to conform to the same canons of science that characterized laboratory research, including accuracy of records, adequate sampling, and data that permit “comprehensive description, measurement, interpretation and even prediction.” He was interested in theoretical frameworks that might have the potential to encompass the complexities of primate social processes, and in his search for unifying principles, he turned, at various times, to sociometry, semiotics, mathematical models, design features of language, dominance hierarchies, homeostasis, and cybernetic functionalism.

In five articles published in 1942 (two), 1952, 1954, and 1958,respectively, Carpenter featured his generalizations about primate grouping and social processes. These eclectic articles include many revelatory statements. Here is a small sample, rearranged and edited for brevity. Most are from Carpenter's two earlier reviews, emphasizing his prescience and eclecticism, which went well beyond that of his contemporaries.

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