An influential argument is that mental processes can be explained at three different levels of analysis: the functional, algorithmic, and implementation level. Identity attribution (the process whereby an identity is attributed to another individual or to the self) has been rarely explored at the functional level. To address this, here I propose a theory of identity attribution grounded on Bayesian inference, being the latter a well-established functional perspective in cognitive science. The theory posits that an identity is inferred based on (...) observations about a target’s features, about the context, and about motivational factors. This inference can be made based upon multiple sources of observations, with prior beliefs becoming more prominent when observations are fewer in number. The theory offers an interpretation of key processes driving identity attribution, potentially providing a platform for integrating different perspectives on identity in psychology and sociology. (shrink)