Editing 1531: The BDLPSWDKS Effect

{{comic
| number    = 1531
| date      = May 29, 2015
| title     = The BDLPSWDKS Effect
| image     = the bdlpswdks effect.png
| titletext = This well-known effect has of course been replicated in countless experiments.
}}

==Explanation==
The BDLPSWDKS Effect in the title is an {{w|acronym}} for Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect, as explained by [[Ponytail]] in the comic. She stands in front of a slide that shows [[Cueball]] being subjected to this effect.

The effect mentioned appears to be a mashup of seven scientific principles (with nine scientists' names included) from physics and social sciences, with elements from each principle appearing in the resulting description of the effect:

*{{w|Bernoulli's principle}} in fluid dynamics (also mentioned in [[803: Airfoil]]) states that an increase in the speed of a fluid with certain properties occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.
** This is referenced by the firetruck lifting off and hurtling.
*The {{w|Doppler effect}} in physics refers to the change in a wave's frequency for an observer moving relative to its source. Sound from the oncoming firetruck increases in pitch.
**This is referenced by Cueball reacting faster if the shouting is in a non-tonal language than a tonal language. In tonal languages, changes in pitch change the meaning, thus tonal languages may suffer more from Doppler distortion than non-tonal ones. Additionally, the choice of firetruck was likely influenced by this effect, as a firetruck and its siren are often invoked as an example of it.
**This may also be referenced by the fact that Cueball reacts faster when red is shouted as the Doppler effect makes light shift up the spectrum : red may still be visible after the shift but green may be out of the visible range. 
*The {{w|Leidenfrost effect}}, in physics, refers to how liquid will produce an insulating vapor layer when in near contact with an extremely hot surface, causing it to hover over said surface.
**This is referenced by the firetruck lifting off on a layer of superheated gas.
*The {{w|Peltzman effect}}, in behavioral economics, refers to how regulations intended to increase safety are ineffective or counterproductive because people, feeling safer, will engage in riskier behaviours.
**This is referenced by the fire truck, which is intended to improve public safety by putting out fires, speeding and thus creating a hazardous situation and reducing the safety of the pedestrian. The firefighter may also be more inclined to drive recklessly due to the feeling of safety they have in a modern firetruck.
*The {{w|Sapir–Whorf hypothesis}}, in linguistics, states that a person's world view and cognitive processes are affected by the structure of the language the person speaks.
**This is referenced by languages with a word for "firefighter" giving a quicker reaction. If Cueball speaks (or is currently thinking in) a language without a word for "firefighter", he might be slower to recognize the role and authority of the driver warning him, and thus slower to react to the danger.
*The {{w|Dunning–Kruger effect}}, in social psychology, refers to unskilled people mistakenly perceiving themselves as more skilled than they really are, while skilled people underestimate their own abilities.
**This is referenced by the tonal language being a language Cueball thinks he is fluent in but isn't.
*The {{w|Stroop effect}}, in psychology, refers to the phenomenon in which it is easier to name the color of the ink in which a word is written when the word refers to the same color as the ink than when the word refers to a different color.
**This is referenced by Cueball diving out faster if the driver screams "red!" than if the driver screams "green!", as a traditional American firetruck is red, and therefore it may create a moment of confusion for Cueball if the driver shouts "green!". It may also reference the common usage of "red" as indicating fire or danger, while "green" indicates safety.

This comic is probably a comment on the "replication crisis" in social psychology which has been in the [http://www.nature.com/news/first-results-from-psychology-s-largest-reproducibility-test-1.17433 news recently]. For example, studies finding that merely thinking about intelligent people (e.g., writing down the attributes of a professor) will actually improve performance on math tests were once widely believed, and this "intelligence priming" effect is even included in textbooks. However, recent attempts to reproduce these effects have mostly failed and this failure to replicate is true of many [http://www.nature.com/news/disputed-results-a-fresh-blow-for-social-psychology-1.12902 social priming effects] as well as other experiments in social psychology. Randall is also mocking the complicated, or even convoluted, setups often used in these experiments.

Usually, for an effect to be considered real, the scientific method requires the effect to be replicated by different experimenters in different times and places. It is hard to imagine several scientists in different parts of the world creating the setup to replicate this effect; however the title text mentions, sarcastically, that it has been done countless times.

Many other XKCD strips have commented on the ease with which surprising and novel, but false, results can be published in the scientific literature, such as [[1478: P-Values]] and [[882: Significant]].

==Transcript==
:[Ponytail stands next to a screen displaying a firetruck hurtling toward Cueball on what appears to be a layer of gas.]

:Ponytail: The Bernoulli-Doppler-Leidenfrost-Peltzman-Sapir-Whorf-Dunning-Kruger-Stroop Effect states that if a speeding fire truck lifts off and hurtles towards you on a layer of superheated gas, you'll dive out of the way faster if the driver screams '''''"red!"''''' in a '''''non'''''-tonal language that '''''has''''' a word for "firefighter" than if they scream '''''"green!"''''' in a '''''tonal''''' language with '''''no''''' word for "firefighter" which you '''''think''''' you're fluent in but '''''aren't'''''.

{{comic discussion}}
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
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[[Category:Physics]]
[[Category:Language]]
[[Category:Psychology]]