Editing Confirmation bias (section)

=== Hypothesis-testing (falsification) explanation (Wason) ===
{{Main|Wason selection task}}

In Peter Wason's initial experiment published in 1960 (which does not mention the term "confirmation bias"), he repeatedly challenged participants to identify a rule applying to triples of numbers. They were told that (2,4,6) fits the rule. They generated triples, and the experimenter told them whether each triple conformed to the rule.<ref name="nickerson"/>{{rp|179}}

The actual rule was simply "any ascending sequence", but participants had great difficulty in finding it, often announcing rules that were far more specific, such as "the middle number is the average of the first and last".<ref>{{Harvnb|Wason|1960}}</ref> The participants seemed to test only positive examples—triples that obeyed their hypothesized rule. For example, if they thought the rule was, "Each number is two greater than its predecessor," they would offer a triple that fitted (confirmed) this rule, such as (11,13,15) rather than a triple that violated (falsified) it, such as (11,12,19).<ref>{{Harvnb|Lewicka|1998|page=238}}</ref>

Wason interpreted his results as showing a preference for confirmation over falsification, hence he coined the term "confirmation bias".{{Efn|Wason also used the term "verification bias".{{Sfn|Poletiek|2001|p=73}}}}<ref name="oswald">{{Harvnb|Oswald|Grosjean|2004|pp=79–96}}</ref> Wason also used confirmation bias to explain the results of his [[Wason selection task|selection task]] experiment.<ref>{{Citation |last=Wason |first=Peter C. |year=1968 |title=Reasoning about a rule |journal=Quarterly Journal of Experimental Psychology |issn= 1747-0226 |volume=20 |issue=3 |pages=273–278 |doi=10.1080/14640746808400161 |pmid=5683766|s2cid=1212273 }}</ref> Participants repeatedly performed badly on various forms of this test, in most cases ignoring information that could potentially refute (falsify) the specified rule.<ref name="sutherland" /><ref>{{Citation |last1=Barkow |first1=Jerome H. |first2=Leda |last2=Cosmides |first3=John |last3=Tooby |title=The adapted mind: evolutionary psychology and the generation of culture |publisher=[[Oxford University Press]] US |year=1995 |pages=[https://archive.org/details/adaptedmindevolu0000unse/page/181 181–184] |isbn=978-0-19-510107-2 |oclc=33832963 |url=https://archive.org/details/adaptedmindevolu0000unse/page/181 }}</ref>