Emotion in animals teeth in aggressive action. A domestic dog's simple tail wag may be used in subtly different ways to convey many meanings as illustrated in Darwin's "The Expression of the Emotions in Man and Animals" published in 1872. Evidence for emotions in animals has been primarily anecdotal, from individuals who interact with pets or captive animals on a regular basis. However, critics of animals having emotions often suggest that anthropomorphism is a motivating factor in the interpretation of the observed behaviours. Much of the debate is caused by the difficulty in defining emotions and the cognitive requirements thought necessary for animals
Darwin from Descent of Man to Emotions our work; and of these you rank as the first." With "the little strength left in me" he reopened his enquiries into earthworms, requesting information from correspondents. The 6th edition of "Origin of Species" was published by Murray on 19 February 1872 at a price kept down to 7s. 6d. by using minute print, and sales increased from 60 to 250 a month. Through the spring Darwin pressed on with "The Expression of the Emotions in Man and Animals", pointing to shared evolution in contrast to Charles Bell's "Anatomy and Physiology of Expression" which claimed divinely created muscles to express