# 46. Logical Manipulation ## 46.5. Methodology/Refinements/Sub-species ### 46.5.9. Congruence bias This is a favourite in the manipulative presentation of test results by both testers and vested interests, trying to use test results to conceal a hidden manipulative payload. Congruence bias occurs because of a victim's over- reliance on direct testing results from a particular (preferred) hypothesis, whilst indirect testing has not been carried out at all. An example will illustrate: Imagine that in an experiment a subject is presented with two buttons and is told that pressing one of those buttons, but not the other, will give a reward. The subject adopts a hypothesis that the button on the right gives a reward. A "direct test" of this theory would be pressing the button on the right and an "indirect test" would be pressing the button on the left. The latter is still a valid test, because once the result of not receiving a reward is proven; the right button is demonstrated to be the desired button. In the case of a victim of manipulation, the manipulator can truthfully say that the button on the right will give a reward. However, this statement is only part of the truth, because it neglects to mention that only the right button gives a reward. Therefore the hypothesis is not totally proven. This phenomenon also occurs as a result of self-delusion, where an experimenter will form a hypothesis, repeatedly get a positive test result and then naively conclude that the hypothesis is therefore completely correct. In such an experiment, a subject will test his own usually naïve hypothesis again and again, instead of trying to disprove it, or test alternate hypotheses. Not only do laboratory animals behave in this way, but also intelligent human beings.