Interviewer beware: behavioral economists have warned us well and good that we suffer from perception bias, in which we seek information that confirms our initial perceptions.

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To give unionists their due, by invoking the "perception" of bias in the courts at least they've taken a slightly more sophisticated line than Sinn Fein politicians who didn't qualify their previous assertions that the PSNI is engaging in "political policing".

BBC: Perception and reality