Confirmation bias is a broad construct covering a number of explanations. Biased search for information, biased interpretation of this information, and biased memory recall, have been invoked to explain four specific effects: 1) "attitude polarization" (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence); 2) "belief perseverance" (when beliefs persist after the evidence for them is shown to be false); 3) the "irrational primacy effect" (a greater reliance on information encountered early in a series); and 4) "illusory correlation" (when people falsely perceive an association between two events or situations).