Confirmation bias

{{bronze}}[[File:ConfirmationBias.jpg|thumb|165px|right]]{{psychology}}{{logic}}
{{cquote|It is true that may hold in these things, which is [[Magical thinking|the general root]] of [[superstition]]; namely, that men observe when things hit, and not when they miss; and commit to memory the one, and forget and pass over the other.|20px|20px|[[Francis Bacon|Sir Francis Bacon]], ''Sylva sylvarum (A natural history in ten centuries)''<ref>https://archive.org/details/worksoffrancisba02bacorich</ref>}}

'''Confirmation bias''', also known as '''observational selection''', '''motivated reasoning''', or '''the enumeration of favorable circumstances''', is the tendency for people to (consciously or ''un''consciously) seek out information that conforms to their pre-existing view points, and subsequently ignore information that goes against them, both positive and negative. It is a type of [[cognitive bias]] and a form of [[selection bias]] toward confirmation of the [[hypothesis]] under study. Avoiding confirmation bias is an important part of [[rationalism]] and in [[science]] in general. This is achieved by setting up problems so that you must find ways of ''disproving'' your hypothesis (see [[falsifiability]]).

==Everyone does it==
Confirmation bias is one of the traits that just comes with the human condition. There is a human tendency to favour testing the predictions of a hypothesis that only confirm or prove it, at the expense of testing any predictions that would disprove a hypothesis. This is a problem because attempts to disprove a hypothesis are the most effective ways of comparing two or more hypotheses, and are also the most informative methods for acquiring evidence. However, even practicing scientists often miss these examples and the [[scientific method]] has basically "[[evolution|evolved]]" to try and counteract it.

In politics, confirmation bias explains, for example, why people with [[right-wing]] views buy right-wing newspapers and why people with left-wing views buy left-wing newspapers (creating [[echo chamber]]s). In general, people both:

*Want to be exposed to information and opinions that confirm what they already believe.
*Have a desire to ignore, or not be exposed to, information or opinions that challenge what they already believe.

Even in cases where people ''do'' expose themselves to alternative points of view, it may be a form of confirmation bias, in that they want to confirm that the opposition is, indeed, wrong.

==Intelligent design==
A prime example stems from the [[intelligent design]] and [[creationism]] movements. Proponents of these ideas start by assuming that an intelligent creator must have been behind life (more than often assuming the [[Christian]] god) and then seeking out any (and only) evidence that might back up this claim. For example, [[Answers in Genesis]] often claims that [[fossils]] in the ground are proof of a [[global flood]] and that layering is caused by the relative abilities of [[animals]] to reach higher grounds. They quote evidence which shows that [[humans]] and other [[primates]] are on top of [[dinosaurs]] in the [[Geologic timeline|geological record]] and claim that this is because we "could climb to higher points on the landscape".

However, they never address any evidence that might disconfirm this hypothesis, such as why angiosperm plants and their pollen is never found below vascular fern fossils, or why we see absolute cut-offs in the fossil record rather than a [[statistical]] tendency, which the "climbing" hypothesis would suggest. (In other words, why weren't there some weak or elderly humans who died with the dinosaurs?) The [[fossil record]] is in fact best explained by [[common descent]], but this is ignored through confirmation bias by creationists.

Creationists, along a similar vein, claim that "[[evolutionist]]s" are practicing confirmation bias, since [[Conspiracy theory|they are all atheists out to distort the scientific record to make it look like God does not exist]]. This claim is, of course [[PRATT|blatantly false]]: the existence of people who believe in [[theistic evolution]] disproves it. Furthermore, not all scientists are [[atheists]], and additionally [[Old Earth creationism|old-earth]] and [[Theory of evolution|evolutionary theories]] were developed by considering ''new'' observations rather than dismissing the old ones. It is, however, true that all [[Young Earth creationism|Young-Earthers]] are [[Theism|theistic]] (as their only real reason for their stance is clinging to [[Biblical literalism|a literal interpretation of]] [[Bible|a ''very'' old book]] that [[Scientific errors in the Bible|asserted several "facts" that rational, properly-educated people in the modern day would know to be incorrect]]).{{fact|joke}}

==Other examples==
A related example to the above is to consider the supremacy of the Bible (and for that matter [[Judaism]] and [[Christianity]]), claiming that cultures and religions of the same area that have similar themes (ie, [[Zoroastrianism]] and its many parallels with Christianity and the [[Sumer|Sumerian]] [[Epic_of_Gilgamesh#Flood_story|version of the Biblical flood]] plus their {{wpl|Enūma_Eliš|Enuma Elish}} and its strong similarities with [[Genesis]]) were influenced by Judaism and its tenets instead of either the opposite happening or everything coming from a common ancestor shared by the cultures of the area, for example ignoring the evidence that points to the former predating the latter if not [[Pious fraud|outright lying]] (ie, Sumerians have a flood story because they were the first post-Flood civilization). Of course and as per the previous example apologists know it's unlikely at best the people whom are told this will check if it's true or not.

==See also==
{{collist|2|
*[[Apophenia]]
*[[Backfire effect]] — the converse effect
*[[Cherry-picking]]
*[[Common sense]]
*[[Bayesian inference]]
*[[Filter bubble]]
*[[Frequency illusion]]
*[[Morton's demon]]
*[[Policy-based evidence making]]
*[[Self-fulfilling prophecy]]
*[[Toupee fallacy]]
*[[Walled garden]]
*[[Willful ignorance]]
}}

==External links==
*David McRaney, [http://youarenotsosmart.com/2010/06/23/confirmation-bias/ ''Confirmation bias''] (youarenotsosmart.com, 23-June 2010)
*Brendan Nyhan and Jason Reifler. [http://www.dartmouth.edu/~nyhan/nyhan-reifler.pdf ''When Corrections Fail: The persistence of political misperceptions'' (pdf)] (Political Behavior, 2006)

==References==
{{reflist}}

{{Cognitive biases}}

[[Category:Cognitive biases]]
[[Category:Logic]]
[[Category:Philosophy of science]]
[[Category:Psychology]]

Categories: Cognitive biases, Logic, Philosophy of science, Psychology