Lloyd Morgan, and the rise and fall of "animal psychology"

Whereas Darwin insisted upon the continuity of human and nonhuman animals, more recent students of animal behavior have largely assumed discontinuity. Lloyd Morgan was a pivotal figure in this transformation. His "canon," although intendend to underpin a psychological approach to animals, has been persistently misunderstood to be a stark prohibition of anthropomorphic description. His extension to animals of the terms "behavior" and "trial-and-error," previously restricted to human psychology, again largely unwittingly devalued their original meaning and widened the gulf between animals and humans. His insistence that knowledge of animal psychology could be trusted solely to "qualified" observers initiated the exclusion from science of the informal and intimate knowledge of animals gained by pet owners, animal trainers, and other scientific outsiders. The presumption, however, that animals, in contrast to people, are to be understood solely as "strangers," begs, rather than addresses, the question of animal-human continuity.