Reasoning 627Figure 23.1 Example of the Wason selection task.
TABLE 23.1 Percentage Correct on Selection Task (Experiment 3)
Rule Type
Given Form Permission Arbitrary Mean
If-then 67 17 42
Only-if 56 4 30
Mean 62 11
Source: From “Pragmatic Reasoning Schemas” by P. W. Cheng and
K. J. Holyoak (1985), Cognitive Psychology, 17,407. Copyright 1985 by
Academic Press. Reprinted by permission.two cards can conclusively test the conditional rule: TheP
card can potentially test the truth or falsity of the rule because
when flipped it might have anot-Qon its other side, and the
not-Qcard can test the rule because when flipped it might
have aPon its other side. The actual conditional rule used in
the Wason selection task isIf there is a vowel on one side of the
card, then there is an even number on the other side of the card,
and the actual cards shown to participants have an exemplar of
either a vowel or a consonant on one side and an even number
or an odd number on the other side. As few as 10% of partici-
pants choose both thePandnot-Qcards (the logically correct
cards), with many more participants choosing either thePcard
by itself or both thePandQcards (Evans & Lynch, 1973;
Wason, 1966, 1983; Wason & Johnson-Laird, 1972; for a re-
view of the task see Evans, Newstead, et al., 1993).
Cheng and Holyoak (1985, 1989) have argued that people
perform poorly on the selection task because it is too abstract
and not meaningful. Their pragmatic reasoning theory grew
out of studies showing that it was possible to improve signif-
icantly participants’ performance on the selection task by
using a meaningful, concrete scenario involving permis-
sions and obligations. Permissionis defined by Cheng and
Holyoak (1985) as a regulation in which, in order to under-
take a particular action, one first must fulfill a particular
precondition. An obligationis defined as a regulation in
which a situation requires the execution of a subsequent
action. In a test of pragmatic reasoning theory, Cheng and
Holyoak (1985) presented participants with the following
permission scenario as an introduction to the selection task:
You are an immigration officer at the International Airport in
Manila, capital of the Philippines. Among the documents you
must check is a sheet called Form H. One side of this form indi-
cates whether the passenger is entering the country or in transit,
and the other side of the form lists inoculations the passenger has
had in the past 6 months. You must make sure thatif the form says
ENTERING on one side, then the other side includes cholera
among the list of diseases. This is to ensure that entering passen-
gers are protected against the disease. Which of the following
forms would you have to turn over to check? (pp. 400– 401)The above introduction was followed by depictions of four
cards in a fashion similar to that shown in Figure 23.1. The first
card depicted the word TRANSIT, another card depicted the
word ENTERING, a third card listed the diseases “cholera,
typhoid, hepatitis,” and a fourth card listed the diseases
“typhoid, hepatitis.” Table 23.1 shows that participants were
significantly more accurate in choosing the correct alterna-
tives,P and not-Q, for the permission task (62 %) than for the
abstract version of the task (11%). In addition, Table 23.1
indicates that the effect of the permission context generalized
across corresponding connective forms; that is, participants’
performance improved not only for permission rules contain-
ing the connectiveif...then,but also for permission rules
containing the equivalent connectiveonly if.
According to Cheng and Holyoak (1985), the permission
schema’s production rules,(1) If the action is to be taken, then the precondition must be
satisfied; and
(2) If the pre-condition is not satisfied, then the action must not be
taken,guided participants’ correct selection of cards by highlighting
the cases where the action was taken (i.e., if the person is en-
tering,then the person must have been inoculated against
cholera) and where the precondition was not satisfied (i.e., if
the person has not been inoculated, then the person must not
enter). According to the theory, reasoning errors occur when
a task’s content fails to elicit an appropriate pragmatic rea-
soning schema. The content of the task must be meaningful
and not arbitrary, however; otherwise, participants perform
as poorly on concrete as on abstract versions of the selection
task (e.g., Manktelow & Evans, 1979).
Despite its success in improving performance on the se-
lection task, pragmatic reasoning theory has been criticized
on a number of grounds. For instance, some investigators
have charged that pragmatic reasoning schemas are better
conceptualized as an undeveloped collection of deonticrules,
which are invoked in situations calling for deontic reasoning.
Manktelow and Over (1991) describe deontic reasoning as