Adaptive bias is the idea that the human brain has evolution to reason adaptively, rather than truthfully or even rationally, and that cognitive bias may have evolved as a mechanism to reduce the overall cost of cognitive errors as opposed to merely reducing the number of cognitive errors, when faced with decision-making under conditions of uncertainty.
Where the cost or impact of a Type I error is much greater than the cost of a Type II error (e.g. the water is safe to drink), it can be worthwhile to bias the decision-making system towards making fewer Type I errors, i.e. making it less likely to conclude that a particular situation exists. This by definition would also increase the number of Type II errors. Conversely, where a false positive is much less costly than a false negative (blood tests, smoke detectors), it makes sense to bias the system towards maximising the probability that a particular (very costly) situation will be recognised, even if this often leads to the (relatively un-costly) event of noticing something that is not actually there. This situation is exhibited in modern airport screening—maximising the probability of preventing a high-cost terrorist event results in frequent, low-cost screening hassles for harmless travelers who represent a minimal threat.
state that cognitive bias can be expected to have developed in humans for cognitive tasks where:
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