Since the BBS article in which Premack and Woodruff
(1978) asked “Does the chimpanzee have a theory of mind?,”
it has been repeatedly claimed that there is observational and
experimental evidence that apes have mental state concepts, such as
“want” and “know.” Unlike research on the
development of theory of mind in childhood, however, no substantial
progress has been made through this work with nonhuman primates.
A survey of empirical studies of imitation, self-recognition, social
relationships, deception, role-taking, and perspective-taking suggests
that in every case where nonhuman primate behavior has been
interpreted as a sign of theory of mind, it could instead have
occurred by chance or as a product of nonmentalistic processes such as
associative learning or inferences based on nonmental categories.
Arguments to the effect that, in spite of this, the theory of mind
hypothesis should be accepted because it is more parsimonious than
alternatives or because it is supported by convergent evidence are not
compelling. Such arguments are based on unsupportable assumptions
about the role of parsimony in science and either ignore the
requirement that convergent evidence proceed from independent
assumptions, or fail to show that it supports the theory of mind
hypothesis over nonmentalist alternatives. Progress in research on
theory of mind requires experimental procedures that can distinguish
the theory of mind hypothesis from nonmentalist alternatives.
A procedure that may have this potential is proposed. It uses
conditional discrimination training and transfer tests to determine
whether chimpanzees have the concept “see.”
Commentators are invited to identify flaws in the procedure
and to suggest alternatives.
Theory of mind in nonhuman primates
