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NLM Announces the Public Release of the Papers of John B. Calhoun, Noted NIH Researcher in Social Crowding and Aggression


The History of Medicine Division of the National Library of Medicine (NLM) announces the public release of the papers of John B. Calhoun (1917-1995), a noted behavioral sciences researcher at the National Institute of Mental Health (NIMH), a component of the National Institutes of Health. From the 1950s through the 1980s, Dr. Calhoun investigated the behavior of mice and rats under conditions of extreme crowding. He, as well as other social scientists, policy makers, and pundits, readily extrapolated his work to comment on human crowding in urban settings, just as the country was undergoing a massive redevelopment of its urban structures. His conclusions found a ready audience among those who saw world overpopulation as not just a problem of resources, but of social cohesion.

In a side note, Calhoun's work with rats inspired the 1971 children's book, Mrs. Frisby and the Rats of NIMH, by Robert C. O'Brien, which was adapted into a 1982 animated film, The Secret of NIMH.

John B. Calhoun was born in Elkton, Tennessee, in 1917. After undergraduate education at the University of Virginia (BA, 1939), and graduate work in zoology at Northwestern University (PhD, 1943), he did post-graduate work and teaching at Emory University, the Ohio State University, and the Johns Hopkins University School of Hygiene and Public Health, studying the ecology and sociology of Norway rats. After further work at the Jackson Memorial Laboratory, Bar Harbor, Maine, and the Army Graduate School at Walter Reed Army Medical Center, in 1954 he joined the Section on Perception in the Laboratory of Psychology at the NIMH. He spent the rest of his career there.

Studying rats under conditions of hyper-crowding, Calhoun observed what he termed the "behavioral sink." This referred to aberrant behaviors such as hyperaggression, failure to breed normally, infant cannibalism, increased mortality, and aberrant sexual patterns in such overcrowded situations. His general conclusion was that "space itself is a necessity." In the 1960s, his research switched into the field of evolution and behavior, which informs the current field of evolutionary psychology. In 1963 he formed and was the first director of NIMH's Unit for Research on Behavioral Systems (URBS) in the Laboratory of Brain Evolution and Behavior (LBEB). He there observed the effects of crowding on a mouse community that was allowed to overpopulate, seeing a complete end to reproduction, with the entire population dying off. Calhoun coined the term "universal autism" to describe the group's behavior at that final point, as they became incapable of the social interaction essential for survival. In the mid-1970s, his research moved in turn to the cultural modes that rats acquired to counteract the effects of overcrowding.

Calhoun retired from NIMH in 1984, but continued to work on his research results until his death on September 7, 1995.

The collection, "MS C 586," comprises 196 linear feet of materials, with records predominantly from 1954 to 1986. It was donated in 1997, as a gift from Edith Calhoun, his widow. In addition to laboratory notebooks and drafts of articles, the collection is particularly noteworthy for the films, videocassettes, and audio reels and cassettes that Dr. Calhoun used to document his experiments.

The Calhoun papers form one of the almost 600 described research collections of the Library's Modern Manuscripts program. They are one of an extensive number in human development and behavioral sciences; others include the papers of Bertram Brown, Wayne Dennis, Lawrence K. Frank, Paul MacLean, Lois Meek, Lois B. Murphy, and Herbert Rowell Stolz, as well as the records of the Society for Research in Child Development, and the American Child Guidance Clinic and Child Psychiatry Movement Interview Collection.

The Calhoun materials may be consulted in the History of Medicine Division Reading Room, National Library of Medicine, open Monday through Friday, from 8:30 a.m. to 5:00 p.m., except federal holidays on the first floor of Building 38 on the NIH campus, Bethesda, Maryland. No appointment is necessary. The finding aid to the collection may be found at;idno=calhoun586 .

The National Library of Medicine, the world's largest biomedical library, is a component of the National Institutes of Health.


Dr. John B. Calhoun points to two tail-wounded mice on his arm from universe 17, study 102. November, 1969.



Dr. John B. Calhoun points to two tail-wounded mice on his arm from universe 17, study 102. November, 1969.

A view of mouse universe 33, showing four cells of group 01 during week 162 of an experiment, possibly study 133. C.1975.

A view of mouse universe 33, showing four cells of group 01 during week 162 of an experiment, possibly study 133. C.1975.