Emotion In Animals

There is no scientific consensus on emotion in animals, that is, what emotions certain species of animals, including humans, feel. The debate concerns primarily mammals and birds, although emotions have also been postulated for other vertebrates and even for some invertebrates.
Animal lovers, scientists, philosophers, and others who interact with animals, have suggested answers but the core question has proven difficult to answer since animals cannot speak of their experience. Society recognizes animals can feel pain as is demonstrated by the criminalization of animal cruelty. Animal expressions of apparent pleasure are ambiguous as to whether this is emotion, or simply innate responses, perhaps for approval or other hard-wired cues. The ambiguity is a source of controversy as there is no certainty which views, if any, reflect reality. That said, extreme behaviourists would say that human "feeling" is also merely a hard-wired response to external stimuli.
In recent years, research has become available which expands prior understandings of animal language, cognition and tool use, and even sexuality. Emotions arise in the mammalian brain, or the limbic system, which human beings share in common with other mammals as well as many other species.