WHAT IS CONFIRMATION BIAS AND WHEN DO PEOPLE ACTUALLY HAVE IT

It is argued here that whether people are seen as thinking scientifically depends on one's view of scientific inquiry. To illustrate, various assumptions were examined about scientific inquiry in the Mynatt, Doherty, and Tweney (1977) work on confirmation bias: (a) Tests to confirm, disconfirm, and suggest alternatives are mutually exclusive; (b) in the face of noncongruent data, hypotheses are to be replaced rather than modified. In contrast, it is argued in the present study that, in scientific inquiry, tests to confirm, disconfirm, and suggest alternatives involve the same strategies and that any test can yield potentially either confirming or disconfirming data. Further, it is often efficient and legitimate to treat hypotheses as working hypotheses to be modified or refined. Two studies are presented that replicate and extend the work of Mynatt et al. It is concluded that college students and college-bound adolescents rarely engage in behavior in the Mynatt et al. task that should be construed as reflecting confirmation bias.