  The idea of animal emotions is, of course, prominent in Darwin's work with his 1872 book The Expression of the Emotions in Man and Animals.  Willingness to see animals as emotional beings (and humans, by contrast, as endowed with rationality that can override the emotions) goes back at least to Ancient Greek philosophy. Konrad Lorenz seems to have held a similar view, echoing Oskar Heinroth's statement that “animals are highly emotional people of very limited intelligence” (Lorenz 1971b, 334). These days it is more fashionable to regard emotions as an important component of intelligence.  Regardless of the merits of that view, the scientific study of animal emotions has gained its own momentum.  Early in the 20th century, although they are not arguing for or about animal consciousness, physiologists recognized that significance of emotion in animal behavior. Dror (1999) explains how the emotional state of animals was considered to be a source of noise in physiological experiments at that time, and researchers took steps to ensure that animals were calm before their experiments.  According to Dror, although physiologists were forced to deal with the problem of emotional noise, attempts to treat emotion as a subject of study in its own right never crystallized to the extent of generating a journal or other institutional features (Dror 1999, 219).