Date of Award

December 2018

Degree Type


Degree Name

Doctor of Philosophy (PhD)




Robert N. Van Gulick


cognitive development, concepts, folk psychology, perception, Perceptual access reasoning, theory of mind

Subject Categories

Arts and Humanities


All human beings understand the behaviors of others as causal results of their mental states. Philosophers call this ability folk psychology and developmental researchers call it theory of mind (ToM). My dissertation concerns how this reasoning works and how it is acquired.

First, I develop and expand a theory of how folk psychology develops in childhood. This is the Perceptual Access Reasoning, or PAR theory of the Fabricius lab. Contrary to the two views dominant in the field, I argue that ToM (belief reasoning or BR) is acquired around 6 years of age after undergoing two preliminary cognitive stages, reality reasoning (RR) and perceptual access reasoning (PAR). Neither of the first two satges of ToM development involve an understanding of mental representation. Evidence for the PAR hypothesis comes from the failure of 4- and 5-year-olds on a false belief task which includes a third, irrelevant, alternative; their failure on true belief tasks; and their failure on no belief tasks. Only the PAR hypothesis can account for all the data. Chapter 2 explains the PAR hypothesis and children’s understanding of believing. Chapter 3 extends the PAR theory to children’s understanding of perception, and demonstrates that the data (mostly tasks testing Flavell’s classic 4 levels model of perception understanding and his appearance/reality distinction) support the PAR hypothesis.

Second, I demonstrate how this theory can be usefully applied to solve problems in cognitive science. In Chapter 4 I explore dual systems theories of cognition (and ToM in particular). In Chapter 5 I solve the Perner-Povinelli Problem—the claim that no empirical test can decide whether subjects are using mentalist rules to pass ToM tasks, or merely using behavioral rules which require no understanding of mental representation. In Chapter 6 I use the PAR hypothesis to argue that a limited theory-theory of concepts is plausible. The PAR stage concept of KNOWING and the adult (BR) concept of KNOWING are fundamentally different because the former is non-representational. Evidence for this is that children in the PAR stage do not distinguish between knowing and guessing correctly, nor between lying and being mistakenly incorrect. The PAR child’s concept of KNOWING is inextricably linked with perceptual access and correct behavior; in other words, with the inferential rules of the PAR theory. I then defend this hypothesis against Fodor’s shareability objection.

Finally, in Chapter 7, I make some specific suggestions for continuing my folk psychology research program by expanding the PAR theory and applying it to other problems in philosophy.


Open Access