Behavioral and Brain Sciences

Open Peer Commentary
Heyes, C. M.: Theory of mind in nonhuman primates

Assessing theory of mind with nonverbal procedures: Problems with training methods and an alternative “key” procedure

Juan Carlos Gómez a1
a1 School of Psychology, University of St. Andrews, St. Andrews KY16 9JU, United Kingdom [email protected]


This commentary criticizes nonverbal methods of assessing theory-of-mind on the basis of prior training of the critical response because they would encourage simple, nonmentalistic, associative solutions even in subjects with mentalistic capacities. I propose instead a new experimental paradigm based upon the use of spontaneous responses in less artificial situations. This method has already provided positive evidence of some level of ToM understanding in nonhuman primates.