The books by Frans de Waal about this topic are very interesting. He's a dutch ethologist, researching the social behaviour and emotions of animals, mainly primates I think.
Some of his quotes, source Wikipedia:
"To endow animals with human emotions has long been a scientific taboo. But if we do not, we risk missing something fundamental, about both animals and us."
"In chimpanzees and other animals, you see examples of sympathy, empathy, reciprocity, a willingness to follow social rules. Dogs are a good example of a species that have and obey social rules; that's why we like them so much, even though they're large carnivores."
Some of his quotes, source Wikipedia:
"To endow animals with human emotions has long been a scientific taboo. But if we do not, we risk missing something fundamental, about both animals and us."
"In chimpanzees and other animals, you see examples of sympathy, empathy, reciprocity, a willingness to follow social rules. Dogs are a good example of a species that have and obey social rules; that's why we like them so much, even though they're large carnivores."