Hypothesis confirmation: The joint effect of positive test strategy and acquiescence response set.

Hypothesis testers tend to ask hypothesis-consistent questions (i.e., they ask about features more likely under the hypothesis than under the alternative). Targets tend to acquiesce (i.e., they provide more yes than no answers). Because yes answers to hypothesis-consistent questions confirm the hypothesis being tested, hypothesis testers should generate hypothesis-confirming data. In the present study, naive hypothesis testers questioned naive targets about their personality traits and, on the basis of targets'answers, drew conclusions about these traits. As predicted, hypothesis testers tended to ask hypothesis-consistent questions, targets tended to acquiesce, and the data generated were consistent with the hypothesis being tested. On the basis of these data, hypothesis testers drew inferences in line with the hypothesis they were testing. Because hypothesis testers derived their conclusions from hypothesis-confirming data, more diagnostic data resulted in a greater confirmation bias