The role of prior expectations in polygraph examiners decisions

In the present experiment, prior expectations were manipulated to examine whether and to what extent polygraph examiners' judgment is affected by their expectations. Each of seven experienced police polygraph examiners examined four innocent subjects suspected of cheating on an aptitude test. The examiners were led to believe that two subjects are probably guilty and the other two are probably innocent. No relationship was found between the final judgment of the examiners and their prior expectations.