Abstract

We make constant use of causal beliefs in our everyday lives without giving much thought to the source of those beliefs, even for situations about which we have no specific prior causal knowledge. We can ask two distinct types of questions about these causal judgments: descriptive questions and normative questions . The primary goal of this dissertation is to apply normative research on causal judgment to our descriptive theories. ;I begin this dissertation by describing the primary results of research on the normative question: the framework of Bayesian networks, and algorithms that provably extract maximal causal information from observations and interventions in the environment. I then show that we can use the framework of Bayesian networks to represent the three major descriptive theories of causal judgment. The three theories are not directly comparable, however, since one of them is algorithmic, while the other two are computational. Therefore, I provide a fully general characterization of the Rescorla-Wagner model. ;With this computational description of the Rescorla-Wagner model in hand, we can compare all three of the theories against the known experimental data. Unfortunately, the experimental data has all been obtained using one particular experimental methodology, which contains serious problems. In addition to critiquing the currently dominant methodology, I provide a "proof of concept" of a different methodology that does not face these problems. ;More importantly, the psychological theories all focus on parameter estimation in a fixed causal structure, rather than learning the actual structure. Therefore, I consider the experimental question: can people learn complex causal structures? The data from those experiments reveal that people appear to use a wide array of learning strategies. The epistemology of our causal beliefs is substantially more complex than has previously been thought. ;Finally, at the end of this dissertation, I step back and examine the implications of these experimental results for descriptive theories of causal judgment. I also point towards several open research questions, both descriptive and normative, raised by the work in this dissertation