Proceedings of the Annual Meeting of the Cognitive Science Society

When several causes contributed to an outcome, we often single out one causal factor as being “more of a cause” than others. What explains this selection? Existing research suggests that people’s judgements of actual causation can be influenced by the degree to which they regard certain events as norm-deviant, or “abnormal” (Hart & Honoré, 1963; Kahneman & Miller, 1986; Hitchcock & Knobe, 2009; Halpern & Hitchcock 2015). In this paper, we argue that statistical abnormality influences causal judgements about human agents by changing the agents’ epistemic states (Epistemic Hypothesis). In Experiment 1, we replicate previous findings that people assign more causal strength to a statistically abnormally acting agent, but show that they also assign them more knowledge about the behaviour of their peers. In Experiment 2, we show that in case of equal epistemic uncertainty, people do not differentiate between statistically abnormal and normal causal agents. In Experiment 3, we explore the difference between type and token abnormality, and find that a token abnormal, but type normal behaviour still influences causal judgments, with people’s epistemic judgments mirroring these causal judgments. We discuss the implications of this research for current norm-frameworks in causal cognition.