Cherry picking

From RationalWiki
Revision as of 11:11, 23 October 2020 by Sqrt-1 (talk | contribs)
Jump to navigation Jump to search
Cogito ergo sum
Logic and rhetoric
Icon logic.svg
Key articles
General logic
Bad logic
If anyone lists a dozen defeats in which the losing side attacked with divided columns, I can list a dozen victories in which that very tactic was employed.
—Carl von Clausewitz, On War, Book Two, Chapter VI[1][2]

Cherry picking, when used figuratively, refers to selective extraction of points in an argument in order to refute or affirm them while ignoring others which will not support the point(s) being made. It derives from the obvious reluctance to harvest unripe, or overripe, fruit and to select only those which will make profit (or pie).

Often, cherry-picked factoids or references will be over-extrapolated and oversold to give the impression that they are representative, when they are not.

Cherry-picking is more a deliberate act of deception than a logical fallacy, but nevertheless an extremely common tactic.

Much of cherry picking is anecdotal evidence, because it only uses one or two examples to make a point; statistical cherry-picking essentially uses larger-scale anecdotes, by ignoring the broader evidence on an issue.

Alternate names

  • argument by selective observation
  • argument by half-truth
  • card stacking
  • confirmation bias
  • coverup (in the form of denialism)
  • fallacy of incomplete evidence
  • fallacy of exclusion
  • fallacy of slanting
  • ignoring counterevidence
  • incomplete/concealed/suppressed evidence
  • observational selection
  • Occam's broom
  • one-sided argument
  • selective use of evidence

Explanation

When presenting a case, omitting important evidence that would hurt one's own case.

In the case of debating creationism vs. evolution, a common suppressed evidence argument would be "Evolution is racist". This is obviously ignoring the evidence that many (in fact most) racist groups who have existed in America are everything but supporting of evolution. Most believe in the Bible as well as creationism. One only needs to look around to see, Ku Klux Klan, Christian Identity, are among the most famous who believe in the statement and claim 'God created races separately' which is actually contradictory to Biblical scriptures. With that said, racism is more associated with creationism than with evolution: by simply denying people of different skin colors have a common ancestor, one is likely racist. The claim also ignores the fact that modern biologists argue that, other than skin color, "race" is not a valid biological concept.

On the other hand, there is the example of Margaret Sanger, the founder of Planned Parenthood, who was staunch believer in evolution (certainly not a "creationist") and a proponent of eugenics (the science of creating and engineering the evolution of humans through breeding those perceived as strong and desirable and eliminating the misfits and the weak).[note 1] One can also note that bringing up Margaret Sanger in an evolution or abortion debate is a genetic fallacy, anyway.

This is not to say evolution is now perfect because creationism is racist (tu quoque). But just to point out the fact that evolution is misused by some in racist actions (eugenics and social Darwinism). It does not mean that evolution is inherently racist, nor does it refute the theory of evolution.

Occam's broom

A variant of cherry picking is Occam's broom; which is used to sweep inconvenient facts under the rug. It's subtly different from cherry picking, because it's just one (or a few) facts that are hidden, rather than a select few that are hand-picked from a large set.

The term was coined by biologist Sidney Brenner.[5]

Examples

Religion

It often occurs that religious fanatics are not altogether in agreement with the holy books and teachings to which they claim to adhere; thus, they are often found cherry-picking points from these holy books, harping on the ones with which they agree and hand-waving away those with which they disagree. Examples:

  • Creationists comb the Bible for quotes that appear to have anticipated scientific truths, such as Hebrews 1:11 (claimed to anticipate the Second Law of Thermodynamics) and Isaiah 40:22 (claimed to anticipate knowledge of the ellipsoidal shape of the earth and the expanding universe), while ignoring those that blatantly clash with science.
  • Reformed Protestants were essentially the inventors of Biblical literalism; but when it comes to verses such as Luke 22:19-20, they insist upon a symbolic interpretation, denying that the blood and body of Jesus is literally present in the Eucharist.
  • On the other hand, the Catholic Church prefers broad allegorical interpretations of Bible stories, and generally downplays the significance of the Bible so as to assert a role for its own "Magisterium;" but when it comes to the Eucharist, they insist upon the literal interpretation, making cannibals and vampires out of partakers in the sacrament.

Pseudohistory

Cherry-picking is common among historical revisionists who may try to smear a group they disagree with by finding a couple people on the other side who were "bad" while only presenting a few people on your own side who were "good".

A golden example of this would be pundits among the hard right who claim, or insinuate, that the dixiecrats weren't conservative because they were Democratic, despite all counterevidence.

Pharmaceutical industry

In the pharmaceutical industry, a "cherry picking protocol" can be part of the drug discovery process. Say you're looking for a drug that'll neutralize Protein XYZ. You take several thousand chemicals whose effects are unknown, and dose a small number of cells in a culture medium with each chemical individually, putting each chemical/cell culture combo in its own separate miniature test tube. You then pass them under a detector that can tell if the cells were affected or not, which records which tubes had a response you're looking for and which didn't. The act of separating out the tubes that had a response, for further testing, is called "hit picking" or "cherry picking."

Automotive industry

A mechanic who chooses to work on newer units in relatively pristine condition, leaving the more intractable and less convenient jobs for others to swear at, could be said to be cherry picking. The same principle is applicable in almost any workplace.

Conspiracy theories

This happens when someone deliberately selects from a wide variety of material only those items which support the conspiracy theory, while ignoring and discarding those which don't. When this carefully chosen selection of material is then presented as a whole, it easily misleads people into thinking that the conspiracy theory is supported by evidence. This is an especially popular tactic for the 9/11 conspiracy theorists: They will only choose those published photographs which support their claims, while outright ignoring those which don't. The Loose ChangeWikipedia Schlockumentary is quite infamous for doing this,[6][7] and pulling it out rather convincingly.

The major problem with this is, of course, that it's pure deception: The viewer is intentionally given only carefully selected material, while leaving out the parts which would contradict the conspiracy theory. This is a deliberate act. The conspiracy theorists cannot claim honesty while doing clear cherry-picking.

Just one example: There's a big electrical transformer box outside the Pentagon which was badly damaged by the plane before it hit the building. It's impossible for that box to get that damage if the building was hit by a missile, as claimed by conspiracy theorists (the missile would have exploded when hitting the box, several tens of meters away from the building). Conspiracy theorists will usually avoid using any photographs which show the damaged transformer box because it contradicts their theory. They are doing this deliberately. They cannot claim honesty while doing this.

Demarcation

You do not commit this fallacy if you:

  • omit minor evidence which is irrelevant to your point. To call this "suppressing evidence" would be quibbling.
  • omit "counterevidence" that has already been falsified. To call this "suppressing evidence" would itself be suppressing evidence, namely the fact that the counterevidence has already been refuted. Creationists do this a lot.

See also

  • The genuine points used in construction of straw man arguments are typically cherry-picked.

External links

Notes

  1. Sanger has been incorrectly attributed as saying some overtly racist things,[3] but she actually worked with African American leaders, including W. E. B. Du Bois, and did not tolerate bigotry among her staff.[4]

References

  1. Clausewitz, Carl von (1993). Paret, Peter; Howard, Michael E.; Brodie, Bernard. eds. On War. New York: Alfred A. Knopf. ISBN 9780679420436. 
  2. Vom Krieg by Carl von Clausewitz
  3. Margaret Sanger Wikiquote.
  4. See the Wikipedia article on Margaret Sanger.
  5. http://www.jbiol.com/content/8/9/79
  6. [https://www.theguardian.com/media/2007/jan/26/digitalmedia 'They're all forced to listen to us'], The Guardian
  7. From Wikipedia