Animal cognition

intelligence of non-human animals

Animal cognition describes the mental capacities of non-human animals and the study of those capacities. Many behaviors associated with the term animal intelligence are also subsumed within animal cognition.

Crab-eating macaque
using a stone tool.


  • [T]here is every reason to believe that we were gregarious animals before we became men... And a belief in the eject—some sort of recognition of a kindred consciousness in one's fellow beings—is clearly a condition of gregarious action among animals so highly developed as to be called conscious at all.
    • William Kingdon Clifford, "On the Nature of Things-in-themselves: Meaning of the Individual Object", Mind (January 1878) as quoted in Lectures and Essays, by the Late William Kingdon Clifford p. 277.
  • It may not be logical, but to my imagination, it is far more satisfactory to look at the young cuckoo ejecting its foster-brothers, ants making slaves, the larvæ of the Ichneumidæ feeding within the live bodies of their prey, cats playing with mice, otters and cormorants with living fish, not as instincts specially given by the Creator, but as very small parts of one general law leading to the advancement of all organic bodies —Multiply, Vary, let the strongest Live and the weakest Die.
  • In general, the form and the structure of the brains of quadrupeds are almost the same as those of the brain of man... with this essential difference, that of all the animals man is the one whose brain is largest, and, in proportion to its mass, more convoluted... then come the monkey, the beaver, the elephant, the dog, the fox, the cat. These animals are most like man, for among them, too, one notes the same progressive analogy in relation to the corpus callosum in which Lancisi—anticipating the late M. de la Peyronie—established the seat of the soul. The latter, however, illustrated the theory by innumerable experiments.
  • Among animals, some learn to speak and sing; they remember tunes, and strike the notes as exactly as a musician. Others, for instance the ape, show more intelligence, and yet can not learn music. What is the reason for this... would it be absolutely impossible to teach the ape a language? I do not think so.
  • In no case may we interpret an action as the outcome of the exercise of a higher psychical faculty, if it can be interpreted as the outcome of the exercise of one which stands lower in the psychological scale.
  • [W]e must steadily bear in mind the sense in which the term "reasoning" is employed. If we apply this term to the process by which an animal, profiting by experience, adapts his actions to somewhat varying circumstances, there can be no hesitation whatever in giving an affirmative answer to the question. ...But there are no grounds for supposing that in the chicken or the horse there is any development of analysis.
  • [T]he phenomena which constitute the subject-matter of Comparative Psychology... have at least as great a claim to accurate classification as those phenomena of structure which constitute the subject-matter of Comparative Anatomy. ...[W]ithin the last twenty years the facts of animal intelligence have suddenly acquired a new and profound importance, from the proved probability of their genetic continuity with those of human intelligence ...[M]y first object ...amounts merely to passing the animal kingdom in review in order to give a trustworthy account of the grade of psychological development which is presented by each group.
    My second, and much more important object, is that of considering the facts of animal intelligence in their relation to the theory of Descent. With the exception of Mr. Darwin's admirable chapters on the mental powers and moral sense, and Mr. Spencer's great work on the Principles of Psychology, there has hitherto been no earnest attempt at tracing the principles which have been probably concerned in the genesis of Mind. ...[T]he present volume... has for its more ultimate purpose the laying of a firm foundation for my future treatise on Mental Evolution.
  • [M]ental activities in other organisms can never be to us objects of direct knowledge... we can only infer their existence from the objective sources supplied by observable activities of such organisms. Therefore all our knowledge of mental activities other than our own really consists of an inferential interpretation of bodily activities—this interpretation being founded on our subjective knowledge of our own mental activities. By inference we project, as it were, the known patterns of our own mental chromograph on what is to us the otherwise blank screen of another mind; and our only knowledge of the processes there taking place is really due to such a projection of our own subjectively. This matter has been well and clearly presented by the late Professor Clifford, who has coined the exceedingly appropriate term eject (in contradistinction to subject and object), whereby to designate the distinctive character of a mind (or mental process) other than our own in its relation to our own. I shall therefore adopt this convenient term, and speak of all our possible knowledge of other minds as ejective.
  • The statements about human nature made by psychologists are of two sorts,—statements about consciousness, about the inner life of thought and feeling, the 'self as conscious,' the 'stream of thought'; and statements about behavior, about the life of man that is left unexplained by physics, chemistry, anatomy and physiology, and is roughly compassed for common sense by the terms 'intellect' and 'character.'
    Animal psychology shows the same double content.

See also