Some people tie themselves in knots, mentally, when they try to be clever about whether people and other animals are clever, is the gist of a study:
“Clever animals and killjoy explanations in comparative psychology,” Sara J. Shettleworth, Trends in Cognitive Science, Volume 14, Issue 11, November 2010, Pages 477-481. The author, at the university of Toronto, Canada, writes:
“From the process of organic evolution to the analysis of insect societies as self-organizing systems, biology is full of awe-inspiring examples of complexity arising from simplicity. Yet in the contemporary study of animal cognition, demonstrations that complex human-like behavior arises from simple mechanisms rather than from ‘higher’ processes, such as insight or theory of mind, are often seen as uninteresting and ‘killjoy’, almost a denial of mental continuity between other species and humans. At the same time, however, research elsewhere in psychology increasingly reveals an unexpected role in human behavior for simple, unconscious and sometimes irrational processes shared by other animals. Greater appreciation of such mechanisms in nonhuman species would contribute to a deeper, more truly comparative psychology.”
BONUS: Shettleworth cites, as the final item in her long list of references, a study by two Ig Nobel Prize winners:
Ghirlanda, S. and Enquist, M. (2003) “A century of generalization,” Anim. Behav. 66, 15–36.