Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only imaginary. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of a system, known and unknown. Philosophical questions about the nature of reality or existence or being are considered under the rubric of ontology, which is a major branch of metaphysics in the Western philosophical tradition. Ontological questions also feature in diverse branches of philosophy, including the philosophy of science, philosophy of religion, philosophy of mathematics, and philosophical logic. These include questions about whether only physical objects are real (i.e., Physicalism), whether reality is fundamentally immaterial (e.g., Idealism), whether hypothetical unobservable entities posited by scientific theories exist, whether God exists, whether numbers and other abstract objects exist, and whether possible worlds exist.
Related concepts
World views and theories
A common colloquial usage would have reality mean
"perceptions, beliefs, and attitudes toward reality", as in "My reality
is not your reality." This is often used just as a colloquialism
indicating that the parties to a conversation agree, or should agree,
not to quibble over deeply different conceptions of what is real. For
example, in a religious discussion between friends, one might say
(attempting humor), "You might disagree, but in my reality, everyone
goes to heaven."
Reality can be defined in a way that links it to worldviews or
parts of them (conceptual frameworks): Reality is the totality of all
things, structures (actual and conceptual), events (past and present)
and phenomena, whether observable or not. It is what a world view
(whether it be based on individual or shared human experience)
ultimately attempts to describe or map.
Certain ideas from physics, philosophy, sociology, literary criticism, and other fields shape various theories of reality. One such belief is that there simply and literally is
no reality beyond the perceptions or beliefs we each have about
reality. Such attitudes are summarized in the popular statement,
"Perception is reality" or "Life is how you perceive reality" or
"reality is what you can get away with" (Robert Anton Wilson), and they indicate anti-realism – that is, the view that there is no objective reality, whether acknowledged explicitly or not.
Philosophy addresses two different aspects of the topic of reality: the nature of reality itself, and the relationship between the mind (as well as language and culture) and reality.
On the one hand, ontology
is the study of being, and the central topic of the field is couched,
variously, in terms of being, existence, "what is", and reality. The
task in ontology is to describe the most general categories of reality
and how they are interrelated. If a philosopher wanted to proffer a
positive definition of the concept "reality", it would be done under
this heading. As explained above, some philosophers draw a distinction
between reality and existence. In fact, many analytic philosophers today
tend to avoid the term "real" and "reality" in discussing ontological
issues. But for those who would treat "is real" the same way they treat
"exists", one of the leading questions of analytic philosophy has been whether existence (or reality) is a property of objects. It has been widely held by analytic philosophers that it is not a property at all, though this view has lost some ground in recent decades.
On the other hand, particularly in discussions of objectivity that have feet in both metaphysics and epistemology, philosophical discussions of "reality" often concern the ways in which reality is, or is not, in some way dependent upon (or, to use fashionable jargon,
"constructed" out of) mental and cultural factors such as perceptions,
beliefs, and other mental states, as well as cultural artifacts, such as
religions and political movements, on up to the vague notion of a common cultural world view, or Weltanschauung.
The view that there is a reality independent of any beliefs, perceptions, etc., is called realism. More specifically, philosophers are given to speaking about "realism about"
this and that, such as realism about universals or realism about the
external world. Generally, where one can identify any class of object,
the existence or essential characteristics of which is said not to
depend on perceptions, beliefs, language, or any other human artifact,
one can speak of "realism about" that object.
One can also speak of anti-realism about the same objects. Anti-realism is the latest in a long series of terms for views opposed to realism. Perhaps the first was idealism, so called because reality was said to be in the mind, or a product of our ideas. Berkeleyan idealism is the view, propounded by the Irish empiricistGeorge Berkeley,
that the objects of perception are actually ideas in the mind. In this
view, one might be tempted to say that reality is a "mental construct";
this is not quite accurate, however, since, in Berkeley's view,
perceptual ideas are created and coordinated by God. By the 20th
century, views similar to Berkeley's were called phenomenalism.
Phenomenalism differs from Berkeleyan idealism primarily in that
Berkeley believed that minds, or souls, are not merely ideas nor made up
of ideas, whereas varieties of phenomenalism, such as that advocated by
Russell,
tended to go farther to say that the mind itself is merely a collection
of perceptions, memories, etc., and that there is no mind or soul over
and above such mental events. Finally, anti-realism became a fashionable term for any
view which held that the existence of some object depends upon the mind
or cultural artifacts. The view that the so-called external world is
really merely a social, or cultural, artifact, called social constructionism, is one variety of anti-realism. Cultural relativism is the view that social issues such as morality are not absolute, but at least partially cultural artifact.
A correspondence theory of knowledge
about what exists claims that "true" knowledge of reality represents
accurate correspondence of statements about and images of reality with
the actual reality that the statements or images are attempting to
represent. For example, the scientific method can verify that a statement is true based on the observable evidence that a thing exists. Many humans can point to the Rocky Mountains and say that this mountain range exists, and continues to exist even if no one is observing it or making statements about it.
Being
The nature of being is a perennial topic in metaphysics. For, instance Parmenides taught that reality was a single unchanging Being, whereas Heraclitus wrote that all things flow. The 20th century philosopher Heidegger
thought previous philosophers have lost sight the question of Being
(qua Being) in favour of the questions of beings (existing things), so
that a return to the Parmenidean approach was needed. An ontological catalogue is an attempt to list the fundamental constituents of reality. The question of whether or not existence is a predicate has been discussed since the Early Modern period, not least in relation to the ontological argument for the existence of God. Existence, that something is, has been contrasted with essence, the question of what something is.
Since existence without essence seems blank, it associated with nothingness by philosophers such as Hegel. Nihilism represents an extremely negative view of being, the absolute a positive one.
Timothy Leary coined the influential term Reality Tunnel, by which he means a kind of representative realism.
The theory states that, with a subconscious set of mental filters
formed from their beliefs and experiences, every individual interprets
the same world differently, hence "Truth is in the eye of the beholder".
His ideas influenced the work of his friend Robert Anton Wilson.
Abstract objects and mathematics
The status of abstract entities, particularly numbers, is a topic of discussion in mathematics.
In the philosophy of mathematics, the best known form of realism about numbers is Platonic realism,
which grants them abstract, immaterial existence. Other forms of
realism identify mathematics with the concrete physical universe.
The traditional debate has focused on whether an abstract (immaterial, intelligible) realm of numbers has existed in addition to the physical (sensible, concrete) world. A recent development is the mathematical universe hypothesis, the theory that only a mathematical world exists, with the finite, physical world being an illusion within it.
An extreme form of realism about mathematics is the mathematical multiverse hypothesis advanced by Max Tegmark. Tegmark's sole postulate is: All structures that exist mathematically also exist physically.
That is, in the sense that "in those [worlds] complex enough to contain
self-aware substructures [they] will subjectively perceive themselves
as existing in a physically 'real' world".
The hypothesis suggests that worlds corresponding to different sets of
initial conditions, physical constants, or altogether different
equations should be considered real. The theory can be considered a form
of Platonism in that it posits the existence of mathematical entities, but can also be considered a mathematical monism in that it denies that anything exists except mathematical objects.
Properties
The problem of universals is an ancient problem in metaphysics about whether universals exist. Universals are general or abstract qualities, characteristics, properties, kinds or relations, such as being male/female, solid/liquid/gas or a certain colour,
that can be predicated of individuals or particulars or that
individuals or particulars can be regarded as sharing or participating
in. For example, Scott, Pat, and Chris have in common the universal
quality of being human or humanity.
The realist school claims that universals are real – they exist
and are distinct from the particulars that instantiate them. There are
various forms of realism. Two major forms are Platonic realism and Aristotelian realism. Platonic realism is the view that universals are real entities and they exist independent of particulars. Aristotelian realism,
on the other hand, is the view that universals are real entities, but
their existence is dependent on the particulars that exemplify them.
A traditional realist position in ontology is that time and space have existence apart from the human mind. Idealists deny or doubt the existence of objects independent of the mind. Some anti-realists
whose ontological position is that objects outside the mind do exist,
nevertheless doubt the independent existence of time and space.
Kant, in the Critique of Pure Reason, described time as an a priori notion that, together with other a priori notions such as space, allows us to comprehend sense experience. Kant denies that either space or time are substance,
entities in themselves, or learned by experience; he holds rather that
both are elements of a systematic framework we use to structure our
experience. Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantitatively compare the interval between (or duration of) events. Although space and time are held to be transcendentally ideal in this sense, they are also empirically real, i.e. not mere illusions.
As well as differing about the reality of time as a whole, metaphysical theories of time can differ in their ascriptions of reality to the past, present and future separately.
Presentism holds that the past and future are unreal, and only an ever-changing present is real.
The block universe
theory, also known as Eternalism, holds that past, present and future
are all real, but the passage of time is an illusion. It is often said
to have a scientific basis in relativity.
The growing block universe theory holds that past and present are real, but the future is not.
The term "possible world" goes back to Leibniz's theory of possible worlds, used to analyse necessity, possibility, and similar modal notions. Modal realism is the view, notably propounded by David Kellogg Lewis, that all possible worlds are as real as the actual world. In short: the actual world is regarded as merely one among an infiniteset of logically possible
worlds, some "nearer" to the actual world and some more remote. Other
theorists may use the Possible World framework to express and explore
problems without committing to it ontologically.
Possible world theory is related to alethic logic: a proposition is necessary if it is true in all possible worlds, and possible if it is true in at least one. The many worlds interpretation of quantum mechanics is a similar idea in science.
Theories of everything (TOE) and philosophy
The philosophical implications of a physical TOE are frequently debated. For example, if philosophical physicalism is true, a physical TOE will coincide with a philosophical theory of everything.
The "system building" style of metaphysics attempts to answer all the important questions in a coherent way, providing a complete picture of the world. Plato and Aristotle
could be said to be early examples of comprehensive systems. In the
early modern period (17th and 18th centuries), the system-building scope of philosophy is often linked to the rationalist method of philosophy, that is the technique of deducing the nature of the world by pure a priori reason. Examples from the early modern period include the Leibniz's Monadology, Descartes's Dualism, Spinoza's Monism. Hegel's Absolute idealism and Whitehead's Process philosophy were later systems.
Other philosophers do not believe its techniques can aim so high.
Some scientists think a more mathematical approach than philosophy is
needed for a TOE, for instance Stephen Hawking wrote in A Brief History of Time
that even if we had a TOE, it would necessarily be a set of equations.
He wrote, "What is it that breathes fire into the equations and makes a
universe for them to describe?"
Phenomenology
On a much broader and more subjective level,
private experiences, curiosity, inquiry, and the selectivity involved
in personal interpretation of events shapes reality as seen by one and
only one person and hence is called phenomenological.
While this
form of reality might be common to others as well, it could at times
also be so unique to oneself as to never be experienced or agreed upon
by anyone else. Much of the kind of experience deemed spiritual occurs on this level of reality.
Phenomenology is a philosophical method developed in the early years of the twentieth century by Edmund Husserl and a circle of followers at the universities of Göttingen and Munich in Germany.
Subsequently, phenomenological themes were taken up by philosophers in
France, the United States, and elsewhere, often in contexts far removed
from Husserl's work.
The word phenomenology comes from the Greekphainómenon, meaning "that which appears", and lógos, meaning "study". In Husserl's conception, phenomenology is primarily concerned with making the structures of consciousness, and the phenomena
which appear in acts of consciousness, objects of systematic reflection
and analysis. Such reflection was to take place from a highly modified "first person"
viewpoint, studying phenomena not as they appear to "my" consciousness,
but to any consciousness whatsoever. Husserl believed that
phenomenology could thus provide a firm basis for all human knowledge, including scientific knowledge, and could establish philosophy as a "rigorous science".
Skeptical hypotheses in philosophy suggest that reality is very
different from what we think it is; or at least that we cannot prove it
is not. Examples include:
The "Brain in a vat"
hypothesis is cast in scientific terms. It supposes that one might be a
disembodied brain kept alive in a vat, and fed false sensory signals,
by a mad scientist. This is a premise of the film series, Matrix hypothesis.
The "Dream argument" of Descartes and Zhuangzi supposes reality to be indistinguishable from a dream.
Descartes' Evil demon is a being "as clever and deceitful as he is powerful, who has directed his entire effort to misleading me."
Moksha – Liberation or Salvation, i.e. the complete annihilation of all karmic matter (bound with any particular soul).
Physical sciences
Scientific realism
Scientific realism is, at the most general level, the view that the world (the universe) described by science (perhaps ideal science) is the real world, as it is, independent of what we might take it to be. Within philosophy of science,
it is often framed as an answer to the question "how is the success of
science to be explained?" The debate over what the success of science
involves centers primarily on the status of entities that are not directly observable discussed by scientific theories.
Generally, those who are scientific realists state that one can make
reliable claims about these entities (viz., that they have the same ontological status) as directly observable entities, as opposed to instrumentalism. The most used and studied scientific theories today state more or less the truth.
Realism and locality in physics
Realism in the sense used by physicists does not equate to realism in metaphysics.
The latter is the claim that the world is mind-independent: that even if
the results of a measurement do not pre-exist the act of measurement,
that does not require that they are the creation of the observer.
Furthermore, a mind-independent property does not have to be the value
of some physical variable such as position or momentum. A property can be dispositional
(or potential), i.e. it can be a tendency: in the way that glass
objects tend to break, or are disposed to break, even if they do not actually
break. Likewise, the mind-independent properties of quantum systems
could consist of a tendency to respond to particular measurements with
particular values with ascertainable probability.
Such an ontology would be metaphysically realistic, without being
realistic in the physicist's sense of "local realism" (which would
require that a single value be produced with certainty).
A closely related term is counterfactual definiteness
(CFD), used to refer to the claim that one can meaningfully speak of
the definiteness of results of measurements that have not been performed
(i.e. the ability to assume the existence of objects, and properties of
objects, even when they have not been measured).
The founders of quantum mechanics debated the role of the observer, and of them, Wolfgang Pauli and Werner Heisenberg believed that it was the observer that produced collapse. This point of view, which was never fully endorsed by Niels Bohr, was denounced as mystical and anti-scientific by Albert Einstein. Pauli accepted the term, and described quantum mechanics as lucid mysticism.
Heisenberg and Bohr always described quantum mechanics in logical positivist terms. Bohr also took an active interest in the philosophical implications of quantum theories such as his complementarity, for example.
He believed quantum theory offers a complete description of nature,
albeit one that is simply ill-suited for everyday experiences – which
are better described by classical mechanics and probability. Bohr never
specified a demarcation line above which objects cease to be quantum and
become classical. He believed that it was not a question of physics,
but one of philosophy.
The structure of the multiverse, the nature of each universe
within it and the relationship between the various constituent
universes, depend on the specific multiverse hypothesis considered.
Multiverses have been hypothesized in cosmology, physics, astronomy, religion, philosophy, transpersonal psychology and fiction, particularly in science fiction and fantasy.
In these contexts, parallel universes are also called "alternative
universes", "quantum universes", "interpenetrating dimensions",
"parallel dimensions", "parallel worlds", "alternative realities",
"alternative timelines", and "dimensional planes", among others.
Scientific theories of everything
A theory of everything (TOE) is a putative theory of theoretical physics that fully explains and links together all known physical phenomena, and predicts the outcome of any experiment that could be carried out in principle. The theory of everything is also called the final theory.
Many candidate theories of everything have been proposed by theoretical
physicists during the twentieth century, but none have been confirmed
experimentally. The primary problem in producing a TOE is that general relativity and quantum mechanics are hard to unify. This is one of the unsolved problems in physics.
Initially, the term "theory of everything" was used with an
ironic connotation to refer to various overgeneralized theories. For
example, a great-grandfather of Ijon Tichy, a character from a cycle of Stanisław Lem's science fiction stories of the 1960s, was known to work on the "General Theory of Everything". Physicist John Ellis claims to have introduced the term into the technical literature in an article in Nature in 1986. Over time, the term stuck in popularizations of quantum physics to describe a theory that would unify or explain through a single model the theories of all fundamental interactions and of all particles of nature: general relativity for gravitation, and the standard model
of elementary particle physics – which includes quantum mechanics – for
electromagnetism, the two nuclear interactions, and the known
elementary particles.
Virtual reality (VR) is a computer-simulated environment that can simulate physical presence in places in the real world, as well as in imaginary worlds.
Reality-virtuality continuum.
The virtuality continuum is a continuous scale ranging between the completely virtual, a virtuality,
and the completely real: reality. The reality–virtuality continuum
therefore encompasses all possible variations and compositions of real
and virtual objects. It has been described as a concept in new media and computer science, but in fact it could be considered a matter of anthropology. The concept was first introduced by Paul Milgram.
The area between the two extremes, where both the real and the virtual are mixed, is the so-called mixed reality. This in turn is said to consist of both augmented reality, where the virtual augments the real, and augmented virtuality, where the real augments the virtual.
Cyberspace,
the world's computer systems considered as an interconnected whole, can
be thought of as a virtual reality; for instance, it is portrayed as
such in the cyberpunk fiction of William Gibson and others. Second Life and MMORPGs such as World of Warcraft are examples of artificial environments or virtual worlds (falling some way short of full virtual reality) in cyberspace.
"RL" in internet culture
On the Internet, "real life" refers to life in the real world. It generally references life or consensus reality, in contrast to an environment seen as fiction or fantasy, such as virtual reality, lifelike experience, dreams, novels, or movies. Online, the acronym "IRL" stands for "in real life", with the meaning "not on the Internet". Sociologists
engaged in the study of the Internet have determined that someday, a
distinction between online and real-life worlds may seem "quaint",
noting that certain types of online activity, such as sexual intrigues,
have already made a full transition to complete legitimacy and
"reality". The abbreviation "RL" stands for "real life". For example, one can speak of "meeting in RL" someone whom one has met in a chat or on an Internet forum. It may also be used to express an inability to use the Internet for a time due to "RL problems"
Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values.
People display this bias when they select information that supports
their views, ignoring contrary information, or when they interpret
ambiguous evidence as supporting their existing attitudes. The effect is
strongest for desired outcomes, for emotionally
charged issues, and for deeply entrenched beliefs. Confirmation bias
cannot be eliminated entirely, but it can be managed, for example, by
education and training in critical thinking skills.
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).
A series of psychological experiments
in the 1960s suggested that people are biased toward confirming their
existing beliefs. Later work re-interpreted these results as a tendency
to test ideas in a one-sided way, focusing on one possibility and
ignoring alternatives (myside bias, an alternative name for
confirmation bias). In general, current explanations for the observed
biases reveal the limited human capacity to process the complete set of
information available, leading to a failure to investigate in a neutral,
scientific way.
Flawed decisions
due to confirmation bias have been found in political, organizational,
financial and scientific contexts. These biases contribute to overconfidence
in personal beliefs and can maintain or strengthen beliefs in the face
of contrary evidence. For example, confirmation bias produces systematic
errors in scientific research based on inductive reasoning
(the gradual accumulation of supportive evidence). Similarly, a police
detective may identify a suspect early in an investigation, but then may
only seek confirming rather than disconfirming evidence. A medical
practitioner may prematurely focus on a particular disorder early in a
diagnostic session, and then seek only confirming evidence. In social media, confirmation bias is amplified by the use of filter bubbles,
or "algorithmic editing", which display to individuals only information
they are likely to agree with, while excluding opposing views.
Definition and context
Confirmation bias, a phrase coined by English psychologist Peter Wason,
is the tendency of people to favor information that confirms or
strengthens their beliefs or values, and is difficult to dislodge once
affirmed. Confirmation bias is an example of a cognitive bias.
Confirmation bias (or confirmatory bias) has also been termed myside bias. "Congeniality bias" has also been used.
Some psychologists restrict the term "confirmation bias" to
selective collection of evidence that supports what one already believes
while ignoring or rejecting evidence that supports a different
conclusion. Others apply the term more broadly to the tendency to
preserve one's existing beliefs when searching for evidence,
interpreting it, or recalling it from memory.
Confirmation bias is a result of automatic, unintentional strategies rather than deliberate deception.
Confirmation bias cannot be avoided or eliminated entirely, but only
managed by improving education and critical thinking skills.
Confirmation bias is a broad construct that has a number of
possible explanations, namely: hypothesis-testing by falsification,
hypothesis testing by positive test strategy, and information processing
explanations.
Types of confirmation bias
Biased search for information
Confirmation bias has been described as an internal "yes man", echoing back a person's beliefs like Charles Dickens' character Uriah Heep
Experiments have found repeatedly that people tend to test hypotheses
in a one-sided way, by searching for evidence consistent with their
current hypothesis.
Rather than searching through all the relevant evidence, they phrase
questions to receive an affirmative answer that supports their theory.
They look for the consequences that they would expect if their
hypothesis were true, rather than what would happen if they were false. For example, someone using yes/no questions to find a number they suspect to be the number 3 might ask, "Is it an odd number?"
People prefer this type of question, called a "positive test", even
when a negative test such as "Is it an even number?" would yield exactly
the same information.
However, this does not mean that people seek tests that guarantee a
positive answer. In studies where subjects could select either such
pseudo-tests or genuinely diagnostic ones, they favored the genuinely
diagnostic.
The preference for positive tests in itself is not a bias, since positive tests can be highly informative.
However, in combination with other effects, this strategy can confirm
existing beliefs or assumptions, independently of whether they are true.
In real-world situations, evidence is often complex and mixed. For
example, various contradictory ideas about someone could each be
supported by concentrating on one aspect of his or her behavior. Thus any search for evidence in favor of a hypothesis is likely to succeed. One illustration of this is the way the phrasing of a question can significantly change the answer.
For example, people who are asked, "Are you happy with your social
life?" report greater satisfaction than those asked, "Are you unhappy with your social life?"
Even a small change in a question's wording can affect how people
search through available information, and hence the conclusions they
reach. This was shown using a fictional child custody case.
Participants read that Parent A was moderately suitable to be the
guardian in multiple ways. Parent B had a mix of salient positive and
negative qualities: a close relationship with the child but a job that
would take them away for long periods of time. When asked, "Which parent
should have custody of the child?" the majority of participants chose
Parent B, looking mainly for positive attributes. However, when asked,
"Which parent should be denied custody of the child?" they looked for
negative attributes and the majority answered that Parent B should be
denied custody, implying that Parent A should have custody.
Similar studies have demonstrated how people engage in a biased
search for information, but also that this phenomenon may be limited by a
preference for genuine diagnostic tests. In an initial experiment,
participants rated another person on the introversion–extroversion
personality dimension on the basis of an interview. They chose the
interview questions from a given list. When the interviewee was
introduced as an introvert, the participants chose questions that
presumed introversion, such as, "What do you find unpleasant about noisy
parties?" When the interviewee was described as extroverted, almost all
the questions presumed extroversion, such as, "What would you do to
liven up a dull party?" These loaded questions gave the interviewees
little or no opportunity to falsify the hypothesis about them.
A later version of the experiment gave the participants less
presumptive questions to choose from, such as, "Do you shy away from
social interactions?"
Participants preferred to ask these more diagnostic questions, showing
only a weak bias towards positive tests. This pattern, of a main
preference for diagnostic tests and a weaker preference for positive
tests, has been replicated in other studies.
Personality traits influence and interact with biased search processes. Individuals vary in their abilities to defend their attitudes from external attacks in relation to selective exposure.
Selective exposure occurs when individuals search for information that
is consistent, rather than inconsistent, with their personal beliefs. An experiment examined the extent to which individuals could refute arguments that contradicted their personal beliefs. People with high confidence
levels more readily seek out contradictory information to their
personal position to form an argument. Individuals with low confidence
levels do not seek out contradictory information and prefer information
that supports their personal position. People generate and evaluate
evidence in arguments that are biased towards their own beliefs and
opinions. Heightened confidence levels decrease preference for information that supports individuals' personal beliefs.
Another experiment gave participants a complex rule-discovery task that involved moving objects simulated by a computer.
Objects on the computer screen followed specific laws, which the
participants had to figure out. So, participants could "fire" objects
across the screen to test their hypotheses. Despite making many attempts
over a ten-hour session, none of the participants figured out the rules
of the system. They typically attempted to confirm rather than falsify
their hypotheses, and were reluctant to consider alternatives. Even
after seeing objective evidence that refuted their working hypotheses,
they frequently continued doing the same tests. Some of the participants
were taught proper hypothesis-testing, but these instructions had
almost no effect.
Biased interpretation of information
Smart people believe weird things because they are skilled at defending beliefs they arrived at for non-smart reasons.
Confirmation biases are not limited to the collection of evidence.
Even if two individuals have the same information, the way they
interpret it can be biased.
A team at Stanford University
conducted an experiment involving participants who felt strongly about
capital punishment, with half in favor and half against it. Each participant read descriptions of two studies: a comparison of U.S. states
with and without the death penalty, and a comparison of murder rates in
a state before and after the introduction of the death penalty. After
reading a quick description of each study, the participants were asked
whether their opinions had changed. Then, they read a more detailed
account of each study's procedure and had to rate whether the research
was well-conducted and convincing. In fact, the studies were fictional. Half the participants were told that one kind of study supported the deterrent effect and the other undermined it, while for other participants the conclusions were swapped.
The participants, whether supporters or opponents, reported
shifting their attitudes slightly in the direction of the first study
they read. Once they read the more detailed descriptions of the two
studies, they almost all returned to their original belief regardless of
the evidence provided, pointing to details that supported their
viewpoint and disregarding anything contrary. Participants described
studies supporting their pre-existing view as superior to those that
contradicted it, in detailed and specific ways.
Writing about a study that seemed to undermine the deterrence effect, a
death penalty proponent wrote, "The research didn't cover a long enough
period of time," while an opponent's comment on the same study said,
"No strong evidence to contradict the researchers has been presented."
The results illustrated that people set higher standards of evidence
for hypotheses that go against their current expectations. This effect,
known as "disconfirmation bias", has been supported by other
experiments.
Another study of biased interpretation occurred during the 2004 U.S. presidential election
and involved participants who reported having strong feelings about the
candidates. They were shown apparently contradictory pairs of
statements, either from Republican candidate George W. Bush, Democratic candidate John Kerry
or a politically neutral public figure. They were also given further
statements that made the apparent contradiction seem reasonable. From
these three pieces of information, they had to decide whether or not
each individual's statements were inconsistent.
There were strong differences in these evaluations, with participants
much more likely to interpret statements from the candidate they opposed
as contradictory.
An MRI scanner allowed researchers to examine how the human brain deals with dissonant information
In this experiment, the participants made their judgments while in a magnetic resonance imaging
(MRI) scanner which monitored their brain activity. As participants
evaluated contradictory statements by their favored candidate, emotional
centers of their brains were aroused. This did not happen with the
statements by the other figures. The experimenters inferred that the
different responses to the statements were not due to passive reasoning
errors. Instead, the participants were actively reducing the cognitive dissonance induced by reading about their favored candidate's irrational or hypocritical behavior.
Biases in belief interpretation are persistent, regardless of intelligence level. Participants in an experiment took the SAT
test (a college admissions test used in the United States) to assess
their intelligence levels. They then read information regarding safety
concerns for vehicles, and the experimenters manipulated the national
origin of the car. American participants provided their opinion if the
car should be banned on a six-point scale, where one indicated
"definitely yes" and six indicated "definitely no". Participants firstly
evaluated if they would allow a dangerous German car on American
streets and a dangerous American car on German streets. Participants
believed that the dangerous German car on American streets should be
banned more quickly than the dangerous American car on German streets.
There was no difference among intelligence levels at the rate
participants would ban a car.
Biased interpretation is not restricted to emotionally
significant topics. In another experiment, participants were told a
story about a theft. They had to rate the evidential importance of
statements arguing either for or against a particular character being
responsible. When they hypothesized that character's guilt, they rated
statements supporting that hypothesis as more important than conflicting
statements.
Biased memory recall of information
People
may remember evidence selectively to reinforce their expectations, even
if they gather and interpret evidence in a neutral manner. This effect
is called "selective recall", "confirmatory memory", or "access-biased
memory". Psychological theories differ in their predictions about selective recall. Schema theory
predicts that information matching prior expectations will be more
easily stored and recalled than information that does not match. Some alternative approaches say that surprising information stands out and so is memorable. Predictions from both these theories have been confirmed in different experimental contexts, with no theory winning outright.
In one study, participants read a profile of a woman which described a mix of introverted and extroverted behaviors.
They later had to recall examples of her introversion and extroversion.
One group was told this was to assess the woman for a job as a
librarian, while a second group were told it was for a job in real
estate sales. There was a significant difference between what these two
groups recalled, with the "librarian" group recalling more examples of
introversion and the "sales" groups recalling more extroverted behavior. A selective memory effect has also been shown in experiments that manipulate the desirability of personality types.
In one of these, a group of participants were shown evidence that
extroverted people are more successful than introverts. Another group
were told the opposite. In a subsequent, apparently unrelated study,
participants were asked to recall events from their lives in which they
had been either introverted or extroverted. Each group of participants
provided more memories connecting themselves with the more desirable
personality type, and recalled those memories more quickly.
Changes in emotional states can also influence memory recall. Participants rated how they felt when they had first learned that O.J. Simpson had been acquitted of murder charges.
They described their emotional reactions and confidence regarding the
verdict one week, two months, and one year after the trial. Results
indicated that participants' assessments for Simpson's guilt changed
over time. The more that participants' opinion of the verdict had
changed, the less stable were the participant's memories regarding their
initial emotional reactions. When participants recalled their initial
emotional reactions two months and a year later, past appraisals closely
resembled current appraisals of emotion. People demonstrate sizable
myside bias when discussing their opinions on controversial topics. Memory recall and construction of experiences undergo revision in relation to corresponding emotional states.
Myside bias has been shown to influence the accuracy of memory recall.
In an experiment, widows and widowers rated the intensity of their
experienced grief six months and five years after the deaths of their
spouses. Participants noted a higher experience of grief at six months
rather than at five years. Yet, when the participants were asked after
five years how they had felt six months after the death of their
significant other, the intensity of grief participants recalled was
highly correlated
with their current level of grief. Individuals appear to utilize their
current emotional states to analyze how they must have felt when
experiencing past events. Emotional memories are reconstructed by current emotional states.
One study showed how selective memory can maintain belief in extrasensory perception (ESP).
Believers and disbelievers were each shown descriptions of ESP
experiments. Half of each group were told that the experimental results
supported the existence of ESP, while the others were told they did not.
In a subsequent test, participants recalled the material accurately,
apart from believers who had read the non-supportive evidence. This
group remembered significantly less information and some of them
incorrectly remembered the results as supporting ESP.
Individual differences
Myside
bias was once believed to be correlated with intelligence; however,
studies have shown that myside bias can be more influenced by ability to
rationally think as opposed to level of intelligence.
Myside bias can cause an inability to effectively and logically
evaluate the opposite side of an argument. Studies have stated that
myside bias is an absence of "active open-mindedness", meaning the
active search for why an initial idea may be wrong.
Typically, myside bias is operationalized in empirical studies as the
quantity of evidence used in support of their side in comparison to the
opposite side.
A study has found individual differences in myside bias. This
study investigates individual differences that are acquired through
learning in a cultural context and are mutable. The researcher found
important individual difference in argumentation. Studies have suggested
that individual differences such as deductive reasoning ability,
ability to overcome belief bias, epistemological understanding, and
thinking disposition are significant predictors of the reasoning and
generating arguments, counterarguments, and rebuttals.
A study by Christopher Wolfe and Anne Britt also investigated how
participants' views of "what makes a good argument?" can be a source of
myside bias that influences the way a person formulates their own
arguments.
The study investigated individual differences of argumentation schema
and asked participants to write essays. The participants were randomly
assigned to write essays either for or against their preferred side of
an argument and were given research instructions that took either a
balanced or an unrestricted approach. The balanced-research instructions
directed participants to create a "balanced" argument, i.e., that
included both pros and cons; the unrestricted-research instructions
included nothing on how to create the argument.
Overall, the results revealed that the balanced-research
instructions significantly increased the incidence of opposing
information in arguments. These data also reveal that personal belief is
not a source of myside bias; however, that those participants,
who believe that a good argument is one that is based on facts, are more
likely to exhibit myside bias than other participants. This evidence is
consistent with the claims proposed in Baron's article—that people's
opinions about what makes good thinking can influence how arguments are
generated.
Before psychological research on confirmation bias, the phenomenon
had been observed throughout history. Beginning with the Greek historian
Thucydides (c. 460 BC – c. 395 BC), who wrote of misguided reason in The Peloponnesian War;
"... for it is a habit of mankind to entrust to careless hope what they
long for, and to use sovereign reason to thrust aside what they do not
fancy".[44] Italian poet Dante Alighieri (1265–1321) noted it in the Divine Comedy, in which St. Thomas Aquinas
cautions Dante upon meeting in Paradise, "opinion—hasty—often can
incline to the wrong side, and then affection for one's own opinion
binds, confines the mind".[45]Ibn Khaldun noticed the same effect in his Muqaddimah:
Untruth naturally afflicts
historical information. There are various reasons that make this
unavoidable. One of them is partisanship for opinions and schools. [...]
if the soul is infected with partisanship for a particular opinion or
sect, it accepts without a moment's hesitation the information that is
agreeable to it. Prejudice and partisanship obscure the critical faculty
and preclude critical investigation. The result is that falsehoods are
accepted and transmitted.
In the Novum Organum, English philosopher and scientist Francis Bacon (1561–1626)
noted that biased assessment of evidence drove "all superstitions,
whether in astrology, dreams, omens, divine judgments or the like". He wrote:
The human understanding when it
has once adopted an opinion ... draws all things else to support and
agree with it. And though there be a greater number and weight of
instances to be found on the other side, yet these it either neglects or
despises, or else by some distinction sets aside or rejects[.]
In the second volume of his The World as Will and Representation (1844), German philosopher Arthur Schopenhauer
observed that "An adopted hypothesis gives us lynx-eyes for everything
that confirms it and makes us blind to everything that contradicts it."
In his essay (1897) "What Is Art?", Russian novelist Leo Tolstoy wrote:
I know that most men—not only those
considered clever, but even those who are very clever, and capable of
understanding most difficult scientific, mathematical, or philosophic
problems—can very seldom discern even the simplest and most obvious
truth if it be such as to oblige them to admit the falsity of
conclusions they have formed, perhaps with much difficulty—conclusions
of which they are proud, which they have taught to others, and on which
they have built their lives.
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 or not each triple conformed to the rule.
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".
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).
Wason interpreted his results as showing a preference for
confirmation over falsification, hence he coined the term "confirmation
bias". Wason also used confirmation bias to explain the results of his selection task experiment.
Participants repeatedly performed badly on various forms of this test,
in most cases ignoring information that could potentially refute
(falsify) the specified rule.
Hypothesis testing (positive test strategy) explanation (Klayman and Ha)
Klayman
and Ha's 1987 paper argues that the Wason experiments do not actually
demonstrate a bias towards confirmation, but instead a tendency to make
tests consistent with the working hypothesis. They called this the "positive test strategy". This strategy is an example of a heuristic: a reasoning shortcut that is imperfect but easy to compute. Klayman and Ha used Bayesian probability and information theory
as their standard of hypothesis-testing, rather than the
falsificationism used by Wason. According to these ideas, each answer to
a question yields a different amount of information, which depends on
the person's prior beliefs. Thus a scientific test of a hypothesis is
one that is expected to produce the most information. Since the
information content depends on initial probabilities, a positive test
can either be highly informative or uninformative. Klayman and Ha argued
that when people think about realistic problems, they are looking for a
specific answer with a small initial probability. In this case,
positive tests are usually more informative than negative tests.
However, in Wason's rule discovery task the answer—three numbers in
ascending order—is very broad, so positive tests are unlikely to yield
informative answers. Klayman and Ha supported their analysis by citing
an experiment that used the labels "DAX" and "MED" in place of "fits the
rule" and "doesn't fit the rule". This avoided implying that the aim
was to find a low-probability rule. Participants had much more success
with this version of the experiment.
If
the true rule (T) encompasses the current hypothesis (H), then positive
tests (examining an H to see if it is T) will not show that the
hypothesis is false.
If the true rule (T) overlaps the current hypothesis (H), then either a negative test or a positive test can potentially falsify H.
When the working hypothesis (H) includes the true rule (T) then positive tests are the only way to falsify H.
In light of this and other critiques, the focus of research moved
away from confirmation versus falsification of an hypothesis, to
examining whether people test hypotheses in an informative way, or an
uninformative but positive way. The search for "true" confirmation bias
led psychologists to look at a wider range of effects in how people
process information.
Information processing explanations
There are currently three main information processing explanations of confirmation bias, plus a recent addition.
Cognitive versus motivational
Happy events are more likely to be remembered.
According to Robert MacCoun, most biased evidence processing occurs through a combination of "cold" (cognitive) and "hot" (motivated) mechanisms.
Cognitive explanations for confirmation bias are based on
limitations in people's ability to handle complex tasks, and the
shortcuts, called heuristics, that they use. For example, people may judge the reliability of evidence by using the availability heuristic that is, how readily a particular idea comes to mind.
It is also possible that people can only focus on one thought at a
time, so find it difficult to test alternative hypotheses in parallel.
Another heuristic is the positive test strategy identified by Klayman
and Ha, in which people test a hypothesis by examining cases where they
expect a property or event to occur. This heuristic avoids the difficult
or impossible task of working out how diagnostic each possible question
will be. However, it is not universally reliable, so people can
overlook challenges to their existing beliefs.
Motivational explanations involve an effect of desire on belief. It is known that people prefer positive thoughts over negative ones in a number of ways: this is called the "Pollyanna principle". Applied to arguments or sources of evidence,
this could explain why desired conclusions are more likely to be
believed true. According to experiments that manipulate the desirability
of the conclusion, people demand a high standard of evidence for
unpalatable ideas and a low standard for preferred ideas. In other
words, they ask, "Can I believe this?" for some suggestions and, "Must I
believe this?" for others. Although consistency
is a desirable feature of attitudes, an excessive drive for consistency
is another potential source of bias because it may prevent people from
neutrally evaluating new, surprising information. Social psychologist Ziva Kunda
combines the cognitive and motivational theories, arguing that
motivation creates the bias, but cognitive factors determine the size of
the effect.
Cost-benefit
Explanations in terms of cost-benefit analysis assume that people do not just test hypotheses in a disinterested way, but assess the costs of different errors. Using ideas from evolutionary psychology, James Friedrich suggests that people do not primarily aim at truth
in testing hypotheses, but try to avoid the most costly errors. For
example, employers might ask one-sided questions in job interviews
because they are focused on weeding out unsuitable candidates.
Yaacov Trope and Akiva Liberman's refinement of this theory assumes
that people compare the two different kinds of error: accepting a false
hypothesis or rejecting a true hypothesis. For instance, someone who
underestimates a friend's honesty might treat him or her suspiciously
and so undermine the friendship. Overestimating the friend's honesty may
also be costly, but less so. In this case, it would be rational to
seek, evaluate or remember evidence of their honesty in a biased way.
When someone gives an initial impression of being introverted or
extroverted, questions that match that impression come across as more empathic. This suggests that when talking to someone who seems to be an introvert, it is a sign of better social skills
to ask, "Do you feel awkward in social situations?" rather than, "Do
you like noisy parties?" The connection between confirmation bias and
social skills was corroborated by a study of how college students get to
know other people. Highly self-monitoring students, who are more sensitive to their environment and to social norms, asked more matching questions when interviewing a high-status staff member than when getting to know fellow students.
Exploratory versus confirmatory
Psychologists Jennifer Lerner and Philip Tetlock distinguish two different kinds of thinking process. Exploratory thought neutrally considers multiple points of view and tries to anticipate all possible objections to a particular position, while confirmatory thought
seeks to justify a specific point of view. Lerner and Tetlock say that
when people expect to justify their position to others whose views they
already know, they will tend to adopt a similar position to those
people, and then use confirmatory thought to bolster their own
credibility. However, if the external parties are overly aggressive or
critical, people will disengage from thought altogether, and simply
assert their personal opinions without justification. Lerner and Tetlock
say that people only push themselves to think critically and logically
when they know in advance they will need to explain themselves to others
who are well-informed, genuinely interested in the truth, and whose
views they don't already know. Because those conditions rarely exist,
they argue, most people are using confirmatory thought most of the time.
Make-believe
Developmental
psychologist Eve Whitmore has argued that beliefs and biases involved
in confirmation bias have their roots in childhood coping through
make-believe, which becomes "the basis for more complex forms of
self-deception and illusion into adulthood." The friction brought on by
questioning as an adolescent with developing critical thinking can lead
to the rationalization of false beliefs, and the habit of such
rationalization can become unconscious over the years.
Real-world effects
Social media
In social media, confirmation bias is amplified by the use of filter bubbles,
or "algorithmic editing", which displays to individuals only
information they are likely to agree with, while excluding opposing
views.
Some have argued that confirmation bias is the reason why society can
never escape from filter bubbles, because individuals are
psychologically hardwired to seek information that agrees with their
preexisting values and beliefs. Others have further argued that the mixture of the two is degrading democracy—claiming
that this "algorithmic editing" removes diverse viewpoints and
information—and that unless filter bubble algorithms are removed, voters
will be unable to make fully informed political decisions.
The rise of social media has contributed greatly to the rapid spread of fake news,
that is, false and misleading information that is presented as credible
news from a seemingly reliable source. Confirmation bias (selecting or
reinterpreting evidence to support one's beliefs) is one of three main
hurdles cited as to why critical thinking goes astray in these
circumstances. The other two are shortcut heuristics (when overwhelmed
or short of time, people rely on simple rules such as group consensus or
trusting an expert or role model) and social goals (social motivation
or peer pressure can interfere with objective analysis of facts at
hand).
In combating the spread of fake news, social media sites have considered turning toward "digital nudging".
This can currently be done in two different forms of nudging. This
includes nudging of information and nudging of presentation. Nudging of
information entails social media sites providing a disclaimer or label
questioning or warning users of the validity of the source while nudging
of presentation includes exposing users to new information which they
may not have sought out but could introduce them to viewpoints that may
combat their own confirmation biases.
Science and scientific research
A distinguishing feature of scientific thinking is the search for confirming or supportive evidence (inductive reasoning) as well as falsifying evidence (deductive reasoning). Inductive research in particular can have a serious problem with confirmation bias.
Many times in the history of science, scientists have resisted new discoveries by selectively interpreting or ignoring unfavorable data.
The assessment of the quality of scientific studies seems to be
particularly vulnerable to confirmation bias. Several studies have shown
that scientists rate studies that report findings consistent with their
prior beliefs more favorably than studies reporting findings
inconsistent with their previous beliefs.
However, assuming that the research question is relevant, the
experimental design adequate and the data are clearly and
comprehensively described, the empirical data obtained should be
important to the scientific community and should not be viewed
prejudicially, regardless of whether they conform to current theoretical
predictions.
In practice, researchers may misunderstand, misinterpret, or not read
at all studies that contradict their preconceptions, or wrongly cite
them anyway as if they actually supported their claims.
Further, confirmation biases can sustain scientific theories or
research programs in the face of inadequate or even contradictory
evidence. The discipline of parapsychology is often cited as an example in the context of whether it is a protoscience or a pseudoscience.
An experimenter's confirmation bias can potentially affect which
data are reported. Data that conflict with the experimenter's
expectations may be more readily discarded as unreliable, producing the
so-called file drawer effect. To combat this tendency, scientific training teaches ways to prevent bias. For example, experimental design of randomized controlled trials (coupled with their systematic review) aims to minimize sources of bias.
The social process of peer review
aims to mitigate the effect of individual scientists' biases, even
though the peer review process itself may be susceptible to such biases. Confirmation bias may thus be especially harmful to objective
evaluations regarding nonconforming results since biased individuals may
regard opposing evidence to be weak in principle and give little
serious thought to revising their beliefs.
Scientific innovators often meet with resistance from the scientific
community, and research presenting controversial results frequently
receives harsh peer review.
Media and fact-checking
Sensationalist
newspapers in the 1850s and later lead to a gradual need for a more
factual media. Colin Dickey has described the subsequent evolution of
fact-checking. Key elements were the establishment of Associated Press in the 1850s (short factual material needed), Ralph Pulitzer
of the New York World (his Bureau of Accuracy and Fair Play, 1912),
Henry Luce and Time magazine (original working title: Facts), and the
famous fact-checking department of The New Yorker.
More recently, the mainstream media has come under severe economic
threat from online startups. In addition the rapid spread of
misinformation and conspiracy theories via social media is slowly
creeping into mainstream media. One solution is for more media staff to
be assigned a fact-checking role, as for example The Washington Post. Independent fact-checking organisations have also become prominent, such as Politifact.
However, the fact-checking of media reports and investigations is
subject to the same confirmation bias as that for peer review of
scientific research. This bias has been little studied so far. For
example, a fact-checker with progressive political views might be more
critical than necessary of a factual report from a conservative
commentator. Another example is that facts are often explained with
ambiguous words, so that progressives and conservatives may interpret
the words differently according to their own beliefs.
Finance
Confirmation bias can lead investors to be overconfident, ignoring evidence that their strategies will lose money. In studies of political stock markets,
investors made more profit when they resisted bias. For example,
participants who interpreted a candidate's debate performance in a
neutral rather than partisan way were more likely to profit. To combat the effect of confirmation bias, investors can try to adopt a contrary viewpoint "for the sake of argument". In one technique, they imagine that their investments have collapsed and ask themselves why this might happen.
Medicine and health
Cognitive
biases are important variables in clinical decision-making by medical
general practitioners (GPs) and medical specialists. Two important ones
are confirmation bias and the overlapping availability bias. A GP may
make a diagnosis early on during an examination, and then seek
confirming evidence rather than falsifying evidence. This cognitive
error is partly caused by the availability of evidence about the
supposed disorder being diagnosed. For example, the client may have
mentioned the disorder, or the GP may have recently read a
much-discussed paper about the disorder. The basis of this cognitive
shortcut or heuristic (termed anchoring) is that the doctor does not
consider multiple possibilities based on evidence, but prematurely
latches on (or anchors to) a single cause.
In emergency medicine, because of time pressure, there is a high
density of decision-making, and shortcuts are frequently applied. The
potential failure rate of these cognitive decisions needs to be managed
by education about the 30 or more cognitive biases that can occur, so as
to set in place proper debiasing strategies. Confirmation bias may also cause doctors to perform unnecessary medical procedures due to pressure from adamant patients.
Raymond Nickerson, a psychologist, blames confirmation bias for
the ineffective medical procedures that were used for centuries before
the arrival of scientific medicine.
If a patient recovered, medical authorities counted the treatment as
successful, rather than looking for alternative explanations such as
that the disease had run its natural course. Biased assimilation is a
factor in the modern appeal of alternative medicine, whose proponents are swayed by positive anecdotal evidence but treat scientific evidence hyper-critically.
Cognitive therapy was developed by Aaron T. Beck in the early 1960s and has become a popular approach. According to Beck, biased information processing is a factor in depression. His approach teaches people to treat evidence impartially, rather than selectively reinforcing negative outlooks. Phobias and hypochondria have also been shown to involve confirmation bias for threatening information.
Politics, law and policing
Mock trials allow researchers to examine confirmation biases in a realistic setting
Nickerson argues that reasoning in judicial and political contexts is
sometimes subconsciously biased, favoring conclusions that judges,
juries or governments have already committed to.
Since the evidence in a jury trial can be complex, and jurors often
reach decisions about the verdict early on, it is reasonable to expect
an attitude polarization effect. The prediction that jurors will become
more extreme in their views as they see more evidence has been borne out
in experiments with mock trials. Both inquisitorial and adversarial criminal justice systems are affected by confirmation bias.
Confirmation bias can be a factor in creating or extending
conflicts, from emotionally charged debates to wars: by interpreting the
evidence in their favor, each opposing party can become overconfident
that it is in the stronger position.
On the other hand, confirmation bias can result in people ignoring or
misinterpreting the signs of an imminent or incipient conflict. For
example, psychologists Stuart Sutherland and Thomas Kida have each argued that U.S. Navy Admiral Husband E. Kimmel showed confirmation bias when playing down the first signs of the Japanese attack on Pearl Harbor.
A two-decade study of political pundits by Philip E. Tetlock
found that, on the whole, their predictions were not much better than
chance. Tetlock divided experts into "foxes" who maintained multiple
hypotheses, and "hedgehogs" who were more dogmatic. In general, the
hedgehogs were much less accurate. Tetlock blamed their failure on
confirmation bias, and specifically on their inability to make use of
new information that contradicted their existing theories.
In police investigations, a detective may identify a suspect
early in an investigation, but then sometimes largely seek supporting or
confirming evidence, ignoring or downplaying falsifying evidence.
Social psychology
Social psychologists have identified two tendencies in the way people seek or interpret information about themselves. Self-verification is the drive to reinforce the existing self-image and self-enhancement is the drive to seek positive feedback. Both are served by confirmation biases.
In experiments where people are given feedback that conflicts with
their self-image, they are less likely to attend to it or remember it
than when given self-verifying feedback. They reduce the impact of such information by interpreting it as unreliable. Similar experiments have found a preference for positive feedback, and the people who give it, over negative feedback.
Mass delusions
Confirmation bias can play a key role in the propagation of mass delusions. Witch trials are frequently cited as an example.
For another example, in the Seattle windshield pitting epidemic,
there seemed to be a "pitting epidemic" in which windshields were
damaged due to an unknown cause. As news of the apparent wave of damage
spread, more and more people checked their windshields, discovered that
their windshields too had been damaged, thus confirming belief in the
supposed epidemic. In fact, the windshields were previously damaged, but
the damage went unnoticed until people checked their windshields as the
delusion spread.
Paranormal beliefs
One factor in the appeal of alleged psychic readings is that listeners apply a confirmation bias which fits the psychic's statements to their own lives.
By making a large number of ambiguous statements in each sitting, the
psychic gives the client more opportunities to find a match. This is one
of the techniques of cold reading, with which a psychic can deliver a subjectively impressive reading without any prior information about the client. Investigator James Randi
compared the transcript of a reading to the client's report of what the
psychic had said, and found that the client showed a strong selective
recall of the "hits".
As a striking illustration of confirmation bias in the real world, Nickerson mentions numerological pyramidology: the practice of finding meaning in the proportions of the Egyptian pyramids. There are many different length measurements that can be made of, for example, the Great Pyramid of Giza
and many ways to combine or manipulate them. Hence it is almost
inevitable that people who look at these numbers selectively will find
superficially impressive correspondences, for example with the
dimensions of the Earth.
Recruitment and selection
Unconscious
cognitive bias (including confirmation bias) in job recruitment affects
hiring decisions and can potentially prohibit a diverse and inclusive
workplace. There are a variety of unconscious biases that affects
recruitment decisions but confirmation bias is one of the major ones,
especially during the interview stage.
The interviewer will often select a candidate that confirms their own
beliefs, even though other candidates are equally or better qualified.
Associated effects and outcomes
Polarization of opinion
When people with opposing views interpret new information in a biased
way, their views can move even further apart. This is called "attitude
polarization".
The effect was demonstrated by an experiment that involved drawing a
series of red and black balls from one of two concealed "bingo baskets".
Participants knew that one basket contained 60 percent black and 40
percent red balls; the other, 40 percent black and 60 percent red. The
experimenters looked at what happened when balls of alternating color
were drawn in turn, a sequence that does not favor either basket. After
each ball was drawn, participants in one group were asked to state out
loud their judgments of the probability that the balls were being drawn
from one or the other basket. These participants tended to grow more
confident with each successive draw—whether they initially thought the
basket with 60 percent black balls or the one with 60 percent red balls
was the more likely source, their estimate of the probability increased.
Another group of participants were asked to state probability estimates
only at the end of a sequence of drawn balls, rather than after each
ball. They did not show the polarization effect, suggesting that it does
not necessarily occur when people simply hold opposing positions, but
rather when they openly commit to them.
A less abstract study was the Stanford biased interpretation
experiment, in which participants with strong opinions about the death
penalty read about mixed experimental evidence. Twenty-three percent of
the participants reported that their views had become more extreme, and
this self-reported shift correlated strongly with their initial
attitudes.
In later experiments, participants also reported their opinions
becoming more extreme in response to ambiguous information. However,
comparisons of their attitudes before and after the new evidence showed
no significant change, suggesting that the self-reported changes might
not be real.
Based on these experiments, Deanna Kuhn and Joseph Lao concluded that
polarization is a real phenomenon but far from inevitable, only
happening in a small minority of cases, and it was prompted not only by
considering mixed evidence, but by merely thinking about the topic.
Charles Taber and Milton Lodge argued that the Stanford team's
result had been hard to replicate because the arguments used in later
experiments were too abstract or confusing to evoke an emotional
response. The Taber and Lodge study used the emotionally charged topics
of gun control and affirmative action.
They measured the attitudes of their participants towards these issues
before and after reading arguments on each side of the debate. Two
groups of participants showed attitude polarization: those with strong
prior opinions and those who were politically knowledgeable. In part of
this study, participants chose which information sources to read, from a
list prepared by the experimenters. For example, they could read the National Rifle Association's and the Brady Anti-Handgun Coalition's
arguments on gun control. Even when instructed to be even-handed,
participants were more likely to read arguments that supported their
existing attitudes than arguments that did not. This biased search for
information correlated well with the polarization effect.
The backfire effect
is a name for the finding that given evidence against their beliefs,
people can reject the evidence and believe even more strongly. The phrase was coined by Brendan Nyhan and Jason Reifler in 2010. However, subsequent research has since failed to replicate findings supporting the backfire effect.
One study conducted out of the Ohio State University and George
Washington University studied 10,100 participants with 52 different
issues expected to trigger a backfire effect. While the findings did
conclude that individuals are reluctant to embrace facts that contradict
their already held ideology, no cases of backfire were detected. The backfire effect has since been noted to be a rare phenomenon rather than a common occurrence.
Persistence of discredited beliefs
[B]eliefs can survive
potent logical or empirical challenges. They can survive and even be
bolstered by evidence that most uncommitted observers would agree
logically demands some weakening of such beliefs. They can even survive
the total destruction of their original evidential bases.
—Lee Ross and Craig Anderson
Confirmation biases provide one plausible explanation for the
persistence of beliefs when the initial evidence for them is removed or
when they have been sharply contradicted.[1]:187 This belief perseverance effect has been first demonstrated experimentally by Festinger, Riecken, and Schachter. These psychologists spent time with a cult whose members were convinced that the world would end
on December 21, 1954. After the prediction failed, most believers still
clung to their faith. Their book describing this research is aptly
named When Prophecy Fails.
The term "belief perseverance," however, was coined in a series
of experiments using what is called the "debriefing paradigm":
participants read fake evidence for a hypothesis, their attitude change
is measured, then the fakery is exposed in detail. Their attitudes are
then measured once more to see if their belief returns to its previous
level.
A common finding is that at least some of the initial belief remains even after a full debriefing.
In one experiment, participants had to distinguish between real and
fake suicide notes. The feedback was random: some were told they had
done well while others were told they had performed badly. Even after
being fully debriefed, participants were still influenced by the
feedback. They still thought they were better or worse than average at
that kind of task, depending on what they had initially been told.
In another study, participants read job performance ratings of two firefighters, along with their responses to a risk aversion test.
This fictional data was arranged to show either a negative or positive
association: some participants were told that a risk-taking firefighter
did better, while others were told they did less well than a risk-averse
colleague.
Even if these two case studies were true, they would have been
scientifically poor evidence for a conclusion about firefighters in
general. However, the participants found them subjectively persuasive.
When the case studies were shown to be fictional, participants' belief
in a link diminished, but around half of the original effect remained.
Follow-up interviews established that the participants had understood
the debriefing and taken it seriously. Participants seemed to trust the
debriefing, but regarded the discredited information as irrelevant to
their personal belief.
The continued influence effect
is the tendency to believe previously learned misinformation even after
it has been corrected. Misinformation can still influence inferences
one generates after a correction has occurred.
Preference for early information
Experiments
have shown that information is weighted more strongly when it appears
early in a series, even when the order is unimportant. For example,
people form a more positive impression of someone described as
"intelligent, industrious, impulsive, critical, stubborn, envious" than
when they are given the same words in reverse order. This irrational primacy effect is independent of the primacy effect in memory in which the earlier items in a series leave a stronger memory trace.
Biased interpretation offers an explanation for this effect: seeing the
initial evidence, people form a working hypothesis that affects how
they interpret the rest of the information.
One demonstration of irrational primacy used colored chips
supposedly drawn from two urns. Participants were told the color
distributions of the urns, and had to estimate the probability of a chip
being drawn from one of them.
In fact, the colors appeared in a prearranged order. The first thirty
draws favored one urn and the next thirty favored the other.
The series as a whole was neutral, so rationally, the two urns were
equally likely. However, after sixty draws, participants favored the urn
suggested by the initial thirty.
Another experiment involved a slide show of a single object, seen
as just a blur at first and in slightly better focus with each
succeeding slide.
After each slide, participants had to state their best guess of what
the object was. Participants whose early guesses were wrong persisted
with those guesses, even when the picture was sufficiently in focus that
the object was readily recognizable to other people.
Illusory association between events
Illusory correlation is the tendency to see non-existent correlations in a set of data. This tendency was first demonstrated in a series of experiments in the late 1960s. In one experiment, participants read a set of psychiatric case studies, including responses to the Rorschach inkblot test.
The participants reported that the homosexual men in the set were more
likely to report seeing buttocks, anuses or sexually ambiguous figures
in the inkblots. In fact the fictional case studies had been constructed
so that the homosexual men were no more likely to report this imagery
or, in one version of the experiment, were less likely to report it than
heterosexual men. In a survey, a group of experienced psychoanalysts reported the same set of illusory associations with homosexuality.
Another study recorded the symptoms experienced by arthritic
patients, along with weather conditions over a 15-month period. Nearly
all the patients reported that their pains were correlated with weather
conditions, although the real correlation was zero.
Example
Days
Rain
No rain
Arthritis
14
6
No arthritis
7
2
This effect is a kind of biased interpretation, in that objectively
neutral or unfavorable evidence is interpreted to support existing
beliefs. It is also related to biases in hypothesis-testing behavior. In judging whether two events, such as illness and bad weather, are correlated, people rely heavily on the number of positive-positive
cases: in this example, instances of both pain and bad weather. They
pay relatively little attention to the other kinds of observation (of no
pain and/or good weather). This parallels the reliance on positive tests in hypothesis testing.
It may also reflect selective recall, in that people may have a sense
that two events are correlated because it is easier to recall times when
they happened together.
