Human uses of mammals that "one is well advised to study the behaviour rather than attempting to get at any underlying emotion". Charles Darwin however had accepted the idea of emotion in animals, writing his 1872 book "The Expression of the Emotions in Man and Animals" on the subject. Darwin believed that mammals had social, mental and moral lives. In "The Descent of Man" (1871), he wrote: "There is no fundamental difference between man and the higher mammals in their mental faculties." Biologists remained wary of the idea, even for the great apes, but this led to serious difficulties, as Donald O. Hebb explained
Body language of dogs emotions, or communicating intentions. Understanding the body language of dogs can also aid in optimal obedience training, as observation of body language may reveal when the dog is most motivated and therefore provides a time-frame whereby dogs will learn more readily. In general, accurately assessing the body language of dogs is quite beneficial as it allows humans to react appropriately to emotions and intentions of the dog. Thus, it fosters successful companionship between the dog owner and pet. Alternatively, ignoring the body language of dogs can pose as a threat for not only humans, but for dogs too. Properly assessing