id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
en-wikipedia-org-8130		Emotion in animals - Wikipedia			.html	text/html	9708	1261	59	Charles Darwin was one of the first scientists to write about the subject, and his observational (and sometimes anecdotal) approach has since developed into a more robust, hypothesis-driven, scientific approach.[2][3][4][5] Cognitive bias tests and learned helplessness models have shown feelings of optimism and pessimism in a wide range of species, including rats, dogs, cats, rhesus macaques, sheep, chicks, starlings, pigs, and honeybees.[6][7][8] Jaak Panksepp played a large role in the study of animal emotion, basing his research on the neurological aspect. Emotion has been observed and further researched through multiple different approaches including that of behaviourism, comparative, anecdotal, specifically Darwin's approach and what is most widely used today the scientific approach which has a number of subfields including functional, mechanistic, cognitive bias tests, self-medicating, spindle neurons, vocalizations and neurology. While emotions in animals is still quite a controversial topic it has been studied in an extensive array of species both large and small including primates, rodents, elephants, horses, birds, dogs, cats, honeybees and crayfish.	./cache/en-wikipedia-org-8130.html	./txt/en-wikipedia-org-8130.txt