The answer lies in the following :-
"The majority of people think you must turn over cards A and 4, the vowel card and the even-number card. It is thought that those who would turn over these cards are thinking "I must turn over A to see if there is an even number on the other side and I must turn over the 4 to see if there is a vowel on the other side." Such thinking supposedly indicates that one is trying to confirm the statement If a card has a vowel on one side, then it has an even number on the other side. Presumably, one is thinking that if the statement cannot be confirmed, it must be false. This explanation then leads to the question: Why do most people try to confirm a statement, when the task is to determine if it is false? One explanation is that people tend to try to fit individual cases into
patterns or rules. The problem with this explanation is that in this case we are instructed to find cases that don't fit the rule. Is there some sort of inherent resistance to such an activity? Are we so driven to fit individual cases to a rule that we can't even follow a simple instruction to find cases that don't fit the rule? Or, are we so driven that we tend to think that the best way to determine whether an instance does not fit a rule is to try to confirm it and if it can't be confirmed then, and only then, do we consider that the rule might be wrong?"
BTW , the answer was "A" and "7" and Jim's explanation was succinct
(marked by compact precise expression without wasted words) unlike the one I read
. Bert's even more so.
Here are two variations :
If a person is drinking beer, then the person is over 19-years-old. (This is supposedly easier because it uses concrete examples in a social setting that people relate to more easily).
18yr , not beer , 19yr , indeterminate age , beer
if there are two primes on one side, the other side must show their product. Pick your numbers and determine the logic you'd apply to determine which cards must be turned round.
[ December 28, 2003: Message edited by: HS Thomas ]