Surse (printre multe altele):
The Descent of Man, a lui Darwin ar fi un bun inceput http://www.infidels.org/library/hist...hapter_05.html,
It has, I think, now been shewn that man and the higher animals, especially the Primates, have some few instincts in common. All have the same senses, intuitions, and sensations,----similar passions, affections, and emotions, even the more complex ones, such as jealousy, suspicion, emulation, gratitude, and magnanimity; they practise deceit and are revengeful; they are sometimes susceptible to ridicule, and even have a sense of humour; they feel wonder and curiosity; they possess the same faculties of imitation, attention, deliberation, choice, memory, imagination, the association of ideas, and reason, though in very different degrees. The individuals of the same species graduate in intellect from absolute imbecility to high excellence. They are also liable to insanity, though far less often than in the case of man.

any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man

cu un rezumat si comentariu aici: http://www.bun.kyoto-u.ac.jp/~suchii/D.onM.html

On the origins of human emotions de J.H. Turner http://books.google.ro/books?id=aEeS...esult&resnum=6

http://www.unep.org/grasp/Informatio.../PR_sept01.asp: I have been studying wild chimpanzees for 36 years and I have come to know that great apes share common emotions, feelings and intelligence with ourselves