Still Suspicious: The Suspicious-Coincidence Effect Revisited

Imagine hearing someone call a particular dalmatian a “dax.” The meaning of the novel noun dax is ambiguous between the subordinate meaning (dalmatian) and the basic-level meaning (dog). Yet both children and adults successfully learn noun meanings at the intended level of abstraction from similar evidence. Xu and Tenenbaum (2007a) provided an explanation for this apparent puzzle: Learners assume that examples are sampled from the true underlying category (strong sampling), making cases in which there are more observed exemplars more consistent with a subordinate meaning than cases in which there are fewer exemplars (the suspicious-coincidence effect). Authors of more recent work (Spencer, Perone, Smith, & Samuelson, 2011) have questioned the relevance of this finding, however, arguing that the effect occurs only when the examples are presented to the learner simultaneously. Across a series of 12 experiments (N = 600), we systematically manipulated several experimental parameters that varied across previous studies, and we successfully replicated the findings of both sets of authors. Taken together, our data suggest that the suspicious-coincidence effect in fact is robust to presentation timing of examples but is sensitive to another factor that varied in the Spencer et al. (2011) experiments, namely, trial order. Our work highlights the influence of pragmatics on behavior in experimental tasks.