You Can Only Self-Represent One Identity at a Time

A cornerstone of cognitive science is that mental systems are limited: There is a maximum amount of information they can process or store, beyond which performance breaks down. Yet so far the study of such limits has been focused on core systems like attention and memory. Here we explore the limit of self-representation, the ability to represent someone or something as you. Using an associative learning paradigm, we find a limit on a well-known index of self-representation known as the self-reference effect, whereby people perform better for items that they represent as themselves than as others. This effect did not continue to scale additively as people associated stimuli with more than one self-identity at a time (e.g., their younger and older selves). This suggests that even though we can represent various identities as the self, we do so independently in serial.