The Expression of the Emotions in Man and Animals in the James-Lange theory of emotions, James develops Darwin's emphasis on the physical aspects, including the visceral (autonomically mediated) components of emotion. In Walter Cannon's "Bodily Changes in Pain, Hunger, Fear and Rage" (1915), Cannon introduces the famous phrase "fight or flight response", formulating emotions in terms of strategies for interpersonal behaviour. More recent psychological theories of emotion have been set out in the Papez-Maclean hypothesis and the Two factor theory of emotion. On 24 January 1895, James Crichton-Browne delivered a notable lecture in Dumfries, Scotland "On Emotional Expression", presenting some of his reservations about Darwin's views. Crichton-Browne argued for
Emotion in animals could be used to include all the animal kingdom as well as some plants. The second approach, mechanistic, requires an examination of the mechanisms that drive emotions and search for similarities in animals. The mechanistic approach is utilized extensively by Paul, Harding and Mendl. Recognizing the difficulty in studying emotion in non-verbal animals, Paul et al. demonstrate possible ways to better examine this. Observing the mechanisms that function in human emotion expression, Paul et al. suggest that concentration on similar mechanisms in animals can provide clear insights into the animal experience. They noted that in humans, cognitive biases vary according