An impressive body of evidence has accumulated demonstrating that many of the judgmental errors' or biases' formerly thought due to purely cognitive shortcomings actually reยฏect the operation of communication goals and strategies that people rely upon to comprehend and generate meaningful conversation. This study examines the eects of individual dierences in conversational skills on the production of biased responses using six judgmental heuristics tasks: base-rate error, conjunction error, dilution eect, underuse of consensus information, primacy eect, and conยฎrmation bias. Clarke's (1975) method of reconstruction' was used to obtain two measures of conversational sophistication: relevance-seeking and (un)responsiveness. A path analysis predicting biased judgments from the skill variables demonstrates that a combination of these variables, which we term Pragmatic Competence', is predictive of two independent subsets of the heuristics tasks. Our model provides convergent evidence with other, parametric studies for the proposition that biased social judgments are, at least in part, artifacts of participants' reasonable (and unreasonable!) expectations concerning experimenter cooperativeness. # 1998 John