Syllogistic Reasoning Task

Syllogistic Reasoning Task R. Walter Heinrichs, Ph.D., Vinod Goel, Ph.D. Instructions to Examiner Give the examinee a copy of the face sheet instructions and read through them while they follow along. The answer to the second problem is “yes,” and to the third problem it is “no.” Proceed to the test itself regardless of whether they answer the practice problems correctly. The time limit for each problem is 1 minute. Record the completion time for each item from 0 to 60 seconds. If they have not responded to the item by 60 seconds say” “Okay, let’s move on to the next one.” The test should take approximately 18 minutes for completion. At the end of administration, use the answer key provided on the last page to total the valid and invalid responses below:

Syllogistic Reasoning Task This is a thinking skills test, which presents you with an argument and asks you to decide whether the conclusion is logically valid or invalid. You will note that each argument has three parts: two statements and a conclusion. The idea is to accept the statements and then decide if the conclusion follows logically. The logical validity of the conclusion does not depend on whether the statements or conclusion are true. Some of these statements involve things that are nonsensical or do not exist. Others involve everyday things that do exist and still others have an emotional or social content. In all cases your job is to decide whether the conclusion is logically valid or invalid. Let’s look at some examples. All foxes are red. No chipmunks are red. Therefore, some chipmunks are not foxes. Is this last statement logically valid? Yes it is, although you might be tempted to add: But no chipmunks are foxes! Everyone knows that chipmunks are not foxes. However, it is the logic that makes the conclusion valid, not your general knowledge. Now try this one: All sensitive men are good lovers. Some impotent men are sensitive. Therefore, some impotent men are good lovers. Is this logically valid? Never mind whether you think it is true, does the conclusion follow logically from the first two statements? This is an example of a problem that has some emotional or social content. Try another: Some ploms are not dihedric. No moduluses are ploms. Therefore, some moduluses are dihedric. Forget that ploms and moduluses are made-up things, is the conclusion logically valid? Although it is possible that some moduluses are dihedric given the first two statements, it is just as possible that no moduluses are dihedric. So the conclusion does not necessarily follow: it’s invalid.

Here are some more examples with the answers given. Feel free to ask the research assistant to help you understand the arguments and answers. All cats are dogs No dogs are lions Therefore, no lions are cats (valid, even though conclusion is false) All fruit are apples. All kiwi are fruit. Therefore, no kiwi are apples. (not valid, even though conclusion is true) All A are B; No B is C Therefore, no C is A (valid) Some A are not B. No C are A. Therefore, some C are B. (not valid)

In the next pages there are 18 of these problems for you to solve. In each case you will be asked to decide whether the conclusion is logically valid or invalid. Work as quickly as you can. Try your best and turn the page to begin!

1.

All codes are highly complex. No quipu are highly complex. Therefore, some quipu are not codes. Valid: _____

Time: _______

NRNSNAAE2.1VNA

Invalid: _____

2.

All handicapped are capable. All amputees are handicapped. Therefore, some amputees are not capable. Valid: _____

Time: _______

BSICAA1.1NVT

Invalid: _____

3.

All flying birds have feathers. No people have feathers. Therefore, some people are flying birds. Valid: _____

Time: _______

BNSCAE2.1NVF

Invalid: _____

4.

No decent girls are bad news. All lesbians are bad news. Therefore, no lesbians are decent girls. Valid: _____

Time: _______

BSICEA2.1VF

Invalid: _____

5.

No harmful substance is natural. All poisons are natural. Therefore, no poisons are harmful. Valid: _____

Time: _______

BNSICEA2.1VF

Invalid: _____

6.

No fruits are fungi. All mushrooms are fungi. Therefore, some mushrooms are fruits. Valid: _____

Time: _______

BNSCEA2.1NVF

Invalid: _____

7.

No isomorphs are cyclically bound. All radix are cyclically bound. Therefore, some isomorphs are radix. Valid: _____

Time: _______

NRNSNAEA2.1NVNA

Invalid: _____

8.

All calculators are machines. All computers are calculators. Therefore, some machines are not computers. Valid: _____

Time: _______

BNSICAA1.1NVT

Invalid: _____

9.

All murderous people are criminals. All Nazis were murderous. Therefore, some Nazis are criminals. Valid: _____

Time: _______

BSCAA1.1VT

Invalid: _____

10. All real functors are mad. All fluxion are real functors. Therefore, some mad things are fluxion. Valid: _____

Time: _______

NRNSNAAA1.1VNA

Invalid: _____

11. No pardoned criminal should be malicious. All rapists are malicious. Therefore, all rapists should be pardoned. Valid: _____

Time: _______

BSCEA2.1NVF

Invalid: _____

12. All shelts are flavoured with basil. Some nimbus nuts are shelts. Therefore, some nimbus nuts are flavoured with basil. Valid: _____

Time: _______ NRNSNAAI1.1VNA

Invalid: _____

13. All psychotics are frauds. Some Biblical prophets were psychotic. Therefore, some Biblical prophets were frauds. Valid: _____

Time: _______ BSCAI1.1VT

Invalid: _____

14. All California snails are amphibians. No amphibian can sing. Therefore, no California snails can sing. Valid: _____

Time: _______

BNSCAE4.1VT

Invalid: _____

15. All perverted people are incestuous. Some families are perverted. Therefore, some families are not incestuous. Valid: _____

Time: _______

BSICAI1.1NVT

Invalid: _____

16. All gentle pets are canines. Some kittens are gentle pets. Therefore, some kittens are canines. Valid: _____

Time: _______

BNSICAI1.2VF

Invalid: _____

17. All monorchids are ground rhumbs. Some rare things are monorchids. Therefore, some ground rhumbs are not rare. Valid: _____

Time: _______

NRNSNAAI1.2NVNA

Invalid: _____

18. Some piggles are cleeved. All piggles are gammas. Therefore, some gammas are not cleeved. Valid: _____

Invalid: _____

Time: _______

NRNSNAIA3.2NVNA

Thank you!

Item* Response 1. 2.i 3.c 4.i 5.i 6.c 7. 8.i 9.c 10. 11.c 12. 13.c 14.c 15.i 16.i 17. 18.

(V) (I) (I) (V) (V) (I) (I) (I) (V) (V) (I) (V) (V) (V) (I) (V) (I) (I)

Answer Key/Record Time Category (sec) non-belief belief-salient belief-non-salient belief-salient belief-non-salient belief-non-salient non-belief belief-non-salient belief-salient non-belief belief-salient non-belief belief-salient belief-non-salient belief-salient belief-non-salient non-belief non-belief

NRNSNAAE2.1VNA BSICAA1.1NVT BNSCAE2.1NVF BSICEA2.1VF BNSICEA2.1VF BNSCEA2.1NVF NRNSNAEA2.1NVNA BNSICAA1.1NVT BSCAA1.1VT NRNSNAAA1.1VNA BSCEA2.1NVF NRNSNAAI1.1VNA BSCAI1.1VT BNSCAE4.1VT BSICAI1.1NVT BNSICAI1.2VF NRNSNAAI1.2NVNA NRNSNAIA3.2NVNA

i = incongruent; c = congruent

Total correct/18: _______ Correct non-belief/6: ________ Correct belief-nonsalient/6: _______ Correct belief-salient/6: ________ Correct congruent/6:____________ Correct incongruent/6:__________ Total completion time: _________ Non-belief completion time: ________ Belief-non-salient completion time: ________ Belief-salient completion time: ____________ Participant code: ______________________ Examiner: ___________________________