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
Body language movement of any part of the body or the body as a whole; in layman's terms, it is the study of body language. However, Ray Birdwhistell, who is considered the founder of this area of study, never used the term "body language", and did not consider it appropriate. He argued that what can be conveyed with the body does not meet the linguist's definition of language. Birdwhistell pointed out that "human gestures differ from those of other animals in that they are polysemic, that they can be interpreted to have many different meanings depending on the communicative context in which