Wason selection task
Encyclopedia
Devised in 1966 by Peter Cathcart Wason
, the Wason selection task, one of the most famous tasks in the psychology of reasoning
, is a logic puzzle
which is formally equivalent to the following question:
A response that identifies a card that need not be inverted, or that fails to identify a card that needs to be inverted, is incorrect. Note that the original task dealt with numbers (even, odd) and letters (vowels, consonants).
Evolutionary psychologists have gathered experimental evidence that people find the Wason task much easier if it is placed in the context of a social rule that the experimental subject is asked to police, suggesting that humans solve the social-rule problem with a specialized mental module that evolved to catch cheaters in a social environment.
in classical logic
.
Some authors have argued that participants do not read "if... then..." as the material conditional, since the natural language conditional is not the material conditional. (See also the paradoxes of the material conditional for more information.) However one interesting feature of the task is how participants react when the classical logic solution is explained:
Leda Cosmides
and John Tooby
identified that the selection task tends to produce the "correct" response when presented in a context of social relation
s. For example, if the rule used is "If you are drinking alcohol then you must be over 18", and the cards have an age on one side and beverage on the other, e.g., "16", "drinking beer", "25", "drinking coke", most people have no difficulty in selecting the correct cards ("16" and "beer"). In a series of experiments in a large number of contexts, subjects demonstrated consistent superior performance when asked to police a social rule involving a benefit that was only legitimately available to someone who had qualified for that benefit. Experimenters have ruled out alternative explanations, such as that people learn the rules of social exchange through practice and find it easier to apply these familiar rules than less-familiar rules.
This experimental evidence supports the hypothesis that a Wason task proves to be easier if the rule to be tested is one of social exchange (in order to receive benefit X you need to fulfill condition Y) and the subject is asked to police the rule, but is more difficult otherwise. Such a distinction, if empirically borne out, would support the contention of evolutionary psychologists
that certain features of human psychology
may be mechanisms that have evolved, through natural selection
, to solve specific problems of social interaction, rather than expressions of general intelligence. In this case, the module is described as a specialized cheater-detection module. Alternatively, it could just mean that there are some linguistic contexts in which people tend to interpret "if" as a material conditional, and other linguistic contexts in which its most common vernacular meaning is different.
Peter Cathcart Wason
Peter Cathcart Wason was a cognitive psychologist, who worked on the psychology of reason. He made great progress in explaining why people make certain consistent mistakes in logical reasoning...
, the Wason selection task, one of the most famous tasks in the psychology of reasoning
Psychology of reasoning
The psychology of reasoning is the study of how people reason, often broadly defined as the process of drawing conclusions to inform how people solve problems and make decisions...
, is a logic puzzle
Logic puzzle
A logic puzzle is a puzzle deriving from the mathematics field of deduction.-History:The logic puzzle was first produced by Charles Lutwidge Dodgson, who is better known under his pen name Lewis Carroll, the author of Alice's Adventures in Wonderland...
which is formally equivalent to the following question:
- You are shown a set of four cards placed on a table, each of which has a number on one side and a colored patch on the other side. The visible faces of the cards show 3, 8, red and brown. Which card(s) must you turn over in order to test the truth of the proposition that if a card shows an even number on one face, then its opposite face is red?
A response that identifies a card that need not be inverted, or that fails to identify a card that needs to be inverted, is incorrect. Note that the original task dealt with numbers (even, odd) and letters (vowels, consonants).
Evolutionary psychologists have gathered experimental evidence that people find the Wason task much easier if it is placed in the context of a social rule that the experimental subject is asked to police, suggesting that humans solve the social-rule problem with a specialized mental module that evolved to catch cheaters in a social environment.
Solution
The correct response was to turn the cards showing 8 and brown, but no other card. Remember how the proposition was stated: "If the card shows an even number on one face, then its opposite face is red." Only a card which has an even number on one face and which is not red on the other face can invalidate this rule. If we turn over the card labeled "3" and find that it is red, this does not invalidate the rule. Likewise, if we turn over the red card and find that it has the label "3", this also does not break the rule. On the other hand, if the brown card has the label "4", this invalidates the rule: it has an even number, but is not red. The interpretation of "if" here is that of the material conditionalMaterial conditional
The material conditional, also known as material implication, is a binary truth function, such that the compound sentence p→q is logically equivalent to the negative compound: not . A material conditional compound itself is often simply called a conditional...
in classical logic
Classical logic
Classical logic identifies a class of formal logics that have been most intensively studied and most widely used. The class is sometimes called standard logic as well...
.
Explanations of performance on the task
In Wason's study, not even 10% of subjects found the correct solution. This result was replicated in 1993.Some authors have argued that participants do not read "if... then..." as the material conditional, since the natural language conditional is not the material conditional. (See also the paradoxes of the material conditional for more information.) However one interesting feature of the task is how participants react when the classical logic solution is explained:
Policing social rules
As of 1983, experimenters had identified that success on the Wason selection task was highly content-dependent, but there was no theoretical explanation for which content elicited mostly correct responses and which ones elicited mostly incorrect responses.Leda Cosmides
Leda Cosmides
Leda Cosmides, is an American psychologist, who, together with anthropologist husband John Tooby, helped develop the field of evolutionary psychology....
and John Tooby
John Tooby
John Tooby is an American anthropologist, who, together with psychologist wife Leda Cosmides, helped pioneer the field of evolutionary psychology....
identified that the selection task tends to produce the "correct" response when presented in a context of social relation
Social relation
In social science, a social relation or social interaction refers to a relationship between two , three or more individuals . Social relations, derived from individual agency, form the basis of the social structure. To this extent social relations are always the basic object of analysis for social...
s. For example, if the rule used is "If you are drinking alcohol then you must be over 18", and the cards have an age on one side and beverage on the other, e.g., "16", "drinking beer", "25", "drinking coke", most people have no difficulty in selecting the correct cards ("16" and "beer"). In a series of experiments in a large number of contexts, subjects demonstrated consistent superior performance when asked to police a social rule involving a benefit that was only legitimately available to someone who had qualified for that benefit. Experimenters have ruled out alternative explanations, such as that people learn the rules of social exchange through practice and find it easier to apply these familiar rules than less-familiar rules.
This experimental evidence supports the hypothesis that a Wason task proves to be easier if the rule to be tested is one of social exchange (in order to receive benefit X you need to fulfill condition Y) and the subject is asked to police the rule, but is more difficult otherwise. Such a distinction, if empirically borne out, would support the contention of evolutionary psychologists
Evolutionary psychology
Evolutionary psychology is an approach in the social and natural sciences that examines psychological traits such as memory, perception, and language from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations, that is, the functional...
that certain features of human psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
may be mechanisms that have evolved, through natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
, to solve specific problems of social interaction, rather than expressions of general intelligence. In this case, the module is described as a specialized cheater-detection module. Alternatively, it could just mean that there are some linguistic contexts in which people tend to interpret "if" as a material conditional, and other linguistic contexts in which its most common vernacular meaning is different.
See also
- CognitionCognitionIn science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
- Confirmation biasConfirmation biasConfirmation bias is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true.David Perkins, a geneticist, coined the term "myside bias" referring to a preference for "my" side of an issue...
- Evolutionary psychologyEvolutionary psychologyEvolutionary psychology is an approach in the social and natural sciences that examines psychological traits such as memory, perception, and language from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations, that is, the functional...
- LogicLogicIn philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...
- Necessary and sufficient conditionsNecessary and sufficient conditionsIn logic, the words necessity and sufficiency refer to the implicational relationships between statements. The assertion that one statement is a necessary and sufficient condition of another means that the former statement is true if and only if the latter is true.-Definitions:A necessary condition...
- Psychology of reasoningPsychology of reasoningThe psychology of reasoning is the study of how people reason, often broadly defined as the process of drawing conclusions to inform how people solve problems and make decisions...
- Reasoning
External links
- Here is the general structure of a Wason selection task — from the Center for Evolutionary Psychology at the University of California, Santa Barbara
- CogLab: Wason Selection — from Wadsworth CogLab 2.0 Cognitive Psychology Online Laboratory
- Elementary My Dear Wason - interactive version of Wason Selection Task at PhilosophyExperiments.Com