
Cherry picking, suppressing evidence, or the fallacy of incomplete evidence is the act of pointing to individual cases or data that seem to confirm a particular position while ignoring a significant portion of related and similar cases or data that may
contradict that position. Cherry picking may be committed intentionally or unintentionally.
The term is based on the perceived process of harvesting fruit, such as
cherries
A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit).
Commercial cherries are obtained from cultivars of several species, such as the sweet ''Prunus avium'' and the sour ''Prunus cerasus''. The name ...
. The picker would be expected to select only the ripest and healthiest fruits. An observer who sees only the selected fruit may thus wrongly conclude that most, or even all, of the tree's fruit is in a likewise good condition. This can also give a false impression of the quality of the fruit (since it is only a sample and is not a
representative sample
In this statistics, quality assurance, and survey methodology, sampling is the selection of a subset or a statistical sample (termed sample for short) of individuals from within a statistical population to estimate characteristics of the whole ...
). A concept sometimes confused with cherry picking is the idea of gathering only the fruit that is easy to harvest, while ignoring other fruit that is higher up on the tree and thus more difficult to obtain (see
low-hanging fruit).
Cherry picking has a negative connotation as the practice neglects, overlooks or directly suppresses evidence that could lead to a complete picture.
Cherry picking can be found in many
logical fallacies. For example, the "fallacy of
anecdotal evidence" tends to overlook large amounts of data in favor of that known personally, "selective use of evidence" rejects material unfavorable to an argument, while a
false dichotomy picks only two options when more are available. Some scholars classify cherry-picking as a
fallacy
A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument that may appear to be well-reasoned if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian '' De Sophisti ...
of selective attention, the most common example of which is the
confirmation bias
Confirmation bias (also confirmatory bias, myside bias, or congeniality bias) is the tendency to search for, interpret, favor and recall information in a way that confirms or supports one's prior beliefs or Value (ethics and social sciences), val ...
. Cherry picking can refer to the selection of data or data sets so a study or survey will give desired, predictable results which may be misleading or even completely contrary to reality.
History
A story about the 5th century
BCE atheist philosopher
Diagoras of Melos
Diagoras of Melos () or Diagoras "the Atheist" was a Greece, Greek poet and sophist of the 5th century BC. Throughout antiquity, he was regarded as an atheism, atheist, but very little is known for certain about what he actually believed. Anecdotes ...
says how, when shown the votive gifts of people who had supposedly escaped death by shipwreck by praying to gods, he pointed out that many people ''had'' died at sea in spite of their prayers, yet these cases were not likewise commemorated (this is an example of
survivorship bias
Survivorship bias or survival bias is the logical error of concentrating on entities that passed a selection process while overlooking those that did not. This can lead to incorrect conclusions because of incomplete data.
Survivorship bias is ...
).
Michel de Montaigne
Michel Eyquem, Seigneur de Montaigne ( ; ; ; 28 February 1533 – 13 September 1592), commonly known as Michel de Montaigne, was one of the most significant philosophers of the French Renaissance. He is known for popularising the the essay ...
(1533–1592) in his
essay on prophecies comments on people willing to believe in the validity of supposed seers:
In science
Cherry picking is one of the epistemological characteristics of
denialism
In the psychology of human behavior, denialism is a person's choice to denial, deny reality as a way to avoid believing in a psychologically uncomfortable truth. Denialism is an essentially irrational action that withholds the validation of a h ...
and widely used by different science
denialists to seemingly contradict scientific findings. For example, it is used in
climate change denial,
evolution denial by creationists, denial of the negative health effects of consuming
tobacco products and passive smoking.
In medicine
In a 2002 study, a review of previous medical data found cherry picking in tests of anti-depression medication:
esearchersreviewed 31 antidepressant efficacy trials to identify the primary exclusion criteria used in determining eligibility for participation. Their findings suggest that patients in current antidepressant trials represent only a minority of patients treated in routine clinical practice for depression. Excluding potential clinical trial subjects with certain profiles means that the ability to generalize the results of antidepressant efficacy trials lacks empirical support, according to the authors.
In argumentation
In argumentation, the practice of "
quote mining" is a form of cherry picking,
in which the debater selectively picks some quotes supporting a position (or exaggerating an opposing position) while ignoring those that moderate the original quote or put it into a different context. Cherry picking in debates is a large problem as the facts themselves are true but need to be put in context. Because research cannot be done live and is often untimely, cherry-picked facts or quotes usually stick in the public mainstream and, even when corrected, lead to widespread misrepresentation of groups targeted.
One-sided argument
A one-sided argument (also known as card stacking, stacking the deck, ignoring the counterevidence, slanting, and suppressed evidence)
is an
informal fallacy
Informal fallacies are a type of incorrect argument in natural language. The source of the error is not just due to the ''form'' of the argument, as is the case for formal fallacies, but can also be due to their ''content'' and ''context''. Fallac ...
that occurs when only the reasons supporting a proposition are supplied, while all reasons opposing it are omitted.
Philosophy professor
Peter Suber
Peter Dain Suber (born November 8, 1951) is an American philosopher specializing in the philosophy of law and open access to knowledge. He is a Senior Researcher at the Berkman Klein Center for Internet & Society, Director of the Harvard Office fo ...
has written:
The one-sidedness fallacy does not make an argument invalid. It may not even make the argument unsound. The fallacy consists in persuading readers, and perhaps ourselves, that we have said enough to tilt the scale of evidence and therefore enough to justify a judgment. If we have been one-sided, though, then we haven't yet said enough to justify a judgment. The arguments on the other side may be stronger than our own. We won't know until we examine them.
So the one-sidedness fallacy doesn't mean that your premises are false or irrelevant, only that they are incomplete.
��You might think that one-sidedness is actually desirable when your goal is winning rather than discovering a complex and nuanced truth. If this is true, then it's true of every fallacy. If winning is persuading a decision-maker, then any kind of manipulation or deception that actually works is desirable. But in fact, while winning may sometimes be served by one-sidedness, it is usually better served by two-sidedness. If your argument (say) in court is one-sided, then you are likely to be surprised by a strong counter-argument for which you are unprepared. The lesson is to cultivate two-sidedness in your thinking about any issue. Beware of any job that requires you to truncate your own understanding.
Card stacking is a
propaganda
Propaganda is communication that is primarily used to influence or persuade an audience to further an agenda, which may not be objective and may be selectively presenting facts to encourage a particular synthesis or perception, or using loaded l ...
technique that seeks to manipulate audience perception of an issue by emphasizing one side and repressing another. Such emphasis may be achieved through
media bias
Media bias occurs when journalists and news producers show bias in how they report and cover news. The term "media bias" implies a pervasive or widespread bias contravening of the standards of journalism, rather than the perspective of an ...
or the use of
one-sided testimonials, or by simply
censoring the voices of critics. The technique is commonly used in persuasive speeches by political candidates to discredit their opponents and to make themselves seem more worthy.
The term originates from the
magician's gimmick of "
stacking the deck", which involves presenting a
deck of cards that appears to have been randomly shuffled but which is, in fact, 'stacked' in a specific order. The magician knows the order and is able to control the outcome of the trick. In poker, cards can be stacked so that certain hands are dealt to certain players.
The phenomenon can be applied to any subject and has wide applications. Whenever a broad spectrum of information exists, appearances can be rigged by highlighting some facts and ignoring others. Card stacking can be a tool of advocacy groups or of those groups with specific agendas. For example, an enlistment poster might focus upon an impressive picture, with words such as "travel" and "adventure", while placing the words, "enlist for two to four years" at the bottom in a smaller and less noticeable point size.
See also
References
{{Propaganda
Inductive fallacies
Cognitive inertia
Metaphors referring to food and drink
Misuse of statistics
Public relations techniques
Evidence
Propaganda techniques