The Time Capsule section of the most recent issue of the American Psychological Association’s Monitor on Psychology features an article on the history of raccoon based comparative research in psychology. Authored by Michael Pettit, “Raccoon intelligence at the borderlands of science: Is it time to bring raccoons back to the psychology laboratory?” provides an overview of the appearance and disappearance of raccoon research in American psychology. Pettit writes,
How does intelligence of raccoons compare with other species? That was a topic of heated debate between 1905 and 1915 within the then-nascent field of comparative psychology.
In 1907, psychologist Lawrence W. Cole, who had established a colony of raccoons at the University of Oklahoma, and Herbert Burnham Davis, a doctoral student at Clark University, each published the results of nearly identical experiments on the processes of learning, association and memory in raccoons. They relied on E.L. Thorndike’s puzzle-box methodology, which involved placing animals in wooden crates from which the animal had to escape by opening the latch or sequence of latches. They observed the number of trials required for successful completion and the extent to which the animal retained the ability to solve the same problem more quickly when confronted again with it. Using this method, they sought what Davis called “a tolerable basis” for ranking the intelligence of raccoons on the phylogenetic scale of evolutionary development. They independently concluded that raccoons bested the abilities of cats and dogs, most closely approximating the mental attributes of monkeys.
Despite this promising start, raccoon research has been rare in psychology since the 1910s.