Causal Reasoning

1. Causal Reasoning GXEX1406 Thinking and Communication Skills

2. What isCausal Reasoning? If you walk on a banana skin you will slip !!!

3. What is Causal Reasoning? • Causal reasoning is a statement about cause and effect. • It is human nature to seek a cause and effect for any circumstances/events/occurrences. • CR attempts to show a definite relationship between things; i.e. one event necessarily causes another. It is a form of inductive reasoning in which an event(s) is the result of another event(s).

4. Definition • One can observe that B follows A, but not that B is caused by A. • A cause must precede its effect. • Example: Studying hard (antecedent) leads to good grades (consequent) • Causal relationships are inferred, not directly observed.

5. Examples of Causal Reasoning • Drinking and driving causes traffic accidents. • A woman with blue eyes will have daughters with blue eyes. • Violence on TV and in movies causes people to like violence

6. How Does CR Work ? • We found that that such an object is followed by such an effect • We foresee other similar objects, will be be followed by similar effects • Example: • The times I touched a hot iron with my bare hands, I was badly burned. __________________________________ • In the future, touching a hot iron will most likely burn my finger.

7. Reasoning Pattern (Mill’s Method Of Reasoning) • There is a set of five careful methods to analyze and interpret our observations for the purpose of drawing conclusions about the causal relationships. • These are Mill’s Method Of Reasoning • In this course we will only consider two of the methods.

8. Mill’s Method Of Reasoning • Method of Agreement • Method of Difference

9. Scenario 1 • In order to illustrate these two methods we consider the following scenario. • Suppose that on an otherwise uneventful afternoon, the Doctor at the Klinik Kesihatan Mahasiswa becomes aware that an unusual number of students from FSKTM are suffering from severe indigestion. • Dr. Adam naturally suspects that this symptom results from something the students ate for lunch, and he would like to find out for sure. (cont)

10. Scenario 1 • The Doctor wants to find evidence that will support a conclusion that "Eating ?xxxx? causes indigestion." • Mill's Methods can help. (cont)

11. Mill’s Method of Agreement • E.g.. Suppose that four students from FSKTM come to see Dr. Adam with indigestion, and he questions each about what they had for lunch. • Dr. Adam: Can you tell me what you had for lunch ? (cont)

12. Mill’s Method of Agreement • First Student (Aziz): I had pizza, roti canai, sugar cane, and an ice cream; • Second Student (Aisha): I had a burger and chips, roti canai, and iced lemon tea; • Third Student (Mary): I ate pizza and roti canai and drank iced lemon tea • Fourth Student(Lim): I ate only chips, roti canai, and papaya. (cont)

13. Mill’s Method of Agreement • Dr. Adam, concludes: • "Eating roti canai caused the indigestion." (cont)

14. Mill’s Method of Agreement • Question: Is eating roti canai the only relevant common factor preceding the indigestion? • Only if it is can the argument be considered reliable. • Question: Could the indigestion be the result of independent causes? (I.e. Maybe there was a viral infection) • The argument is reliable only if this possibility has been eliminated.

15. Mill’s First Method (Method of Agreement) • Generally, • X is the common thread. • X causedYbecauseXis the only relevant common factor in more than one occurrence ofY.

16. Mill’s Method of Agreement • Question: Is X the only relevant common factor preceding the occurrences of Y? • Only if it is can the argument be considered reliable. • Question: Did the occurrences of Y result from independent causes? • The argument is reliable only if this possibility has been eliminated.

17. Mill's Method of Difference • On the other hand, suppose that only two students arrive at the Klinik. • The two are roommates who ate together, but one became ill while the other did not. • The first had eaten a burger, chips, roti canai, papaya and drank iced lemon tea, • The other had eaten a burger, chips, papaya, and drank iced lemon tea. • Again, Dr. Adam concludes that the roti canai is what made the first roommate ill. (cont)

18. Mill's Method of Difference • This reasoning applies : comparison of a case in which the effect occurred and another case in which the effect did not occur revealed that only one prior circumstance was present in the first case but not in the second. • In such situations, we commonly suppose that, other things being equal, different effects are likely to arise from different causes, and since only the student who had eaten roti canai became ill, it was probably the cause. (cont)

19. Mill's Method of Difference • Roti Canai is the difference. • Roti Canai caused indigestion because roti canai is the only relevant difference between this situation, where indigestion occurred, and situations where indigestion did not occur.

20. Mill's Method of Difference • Question: Is eating roti canai the only relevant common factor preceding the indigestion? • Only if it is can the argument be considered reliable. • Could the indigestion be the result of independent causes? (Again, the viral infection) • The argument is reliable only if this possibility has been eliminated.

21. Mill’s 2nd Method(Method of Difference) • Generally, • X is the difference. • X caused Y because X is the only relevant difference between this situation, where Y occurred, and situations where Y did not occur.

22. Mill’s 2nd Method • Question: Is X the only relevant common factor preceding the occurrences of Y? (Only if it is can the argument be considered reliable.) Did the occurrences of Y result from independent causes? (The argument is reliable only if this possibility has been eliminated.)

23. Fallacies of Causality • Questionable Cause aka Ignoring a Common Cause • Assuming a Common Cause • Misidentification of the Cause • Slippery Slope • post hoc ergo propter hoc

24. Fallacies of Causality:Questionable Cause • This fallacy occurs when someone presents a causal relationship for which no real evidence exists. • AKA Ignoring a Common Cause • This fallacy has the following general structure: • X and Y are associated on a regular basis. (but no third, common cause is looked for). • Therefore X is the cause of Y. (cont)

25. Fallacies of Causality:Questionable Cause • The general idea behind this fallacy is that it is an error in reasoning to conclude that one thing causes another simply because the two are associated on a regular basis. • More formally, this fallacy is committed when it is concluded that X is the cause of Y simply because they are associated on a regular basis. • The error being made is that a causal conclusion is being drawn from inadequate evidence. • Further, the causal conclusion is drawn without considering the possibility that a third factor might be the cause of both X and Y. (cont)

26. Examples of Questionable Cause Example 1 • Ali gets a chain email that threatens him with dire consequences if he breaks the chain. • He laughs at it and throws it in the rubbish bin. • On his way to work he slips and breaks his leg. • When he gets back from the hospital he sends out 200 copies of the chain letter, hoping to avoid further accidents. (cont)

27. Examples of Questionable Cause Example 2 • A thunderstorm wakes Tan up in the middle of the night. • He goes downstairs to get some milk to help him get back to sleep. • On the way to the refrigerator, he notices that the barometer has fallen a great deal. • Tan concludes that the storm caused the barometer to fall. • In the morning he tells his wife about his conclusion. • She tells him that it was a drop in atmospheric pressure that caused the barometer to drop and the storm. (cont)

28. Fallacies of Causality:Assuming a Common Cause • This is the reverse of Ignoring a Common Cause (Questionable Cause) • It consists of automatically assuming that two conjoined events must have had the same underlying cause. • This fallacy occurs by claiming a link between X and Y when none exists. • The moral is, "Don't unthinkingly assume that two conjoined occurrences have a common cause. • But don't unthinkingly assume that they do not, either". (cont)

29. Examples of Assuming a Common Cause • "Both physicians ended up with cancer. • There must be something about treating sickness that makes you get cancer.“

30. Fallacies of Causality:Misidentification of the Cause • In causal situations, we are not always certain about what is causing what. • i.e. what is the cause and what is the effect. • E.g.. "Headaches and tension" • "Failure is school and personal problems“ (cont)

31. Fallacies of Causality:Slippery Slope: • One undesirable action will lead to a worse action, which will lead to a worse one still, all the way down the 'slippery slope' to some terrible disaster at the bottom. • Although this progression my indeed happen, there is certainly no causal guarantee that it will. (cont)

32. Examples of Slippery Slope • If we let this lady check 11 items through the 6 item express checkout, you'll next be letting people walk out the store without paying, then speeding, murder and mayhem will be allowed, the country will go to …

33. Fallacies of Causality:post hoc ergo propter hoc • Causality plays such a dominant role in our lives, and many a time mistakes or faulty reasoning occur. • post hoc fallacy • The post hoc ergo propter hoc (after this therefore because of this) fallacy is based upon the mistaken notion that simply because one thing happens after another, the first event was a cause of the second event. • Post hoc reasoning is the basis for many superstitions and erroneous beliefs. (cont)

34. Examples of post hoc ergo propter hoc • You have a cold, so you drink fluids and two weeks later your cold goes away. • You have a headache so you stand on your head and six hours later your headache goes away. • You put acne medication on a pimple and three weeks later the pimple goes away.

35. Testing Causal Relationships • Is the cause necessary to produce the effect? • E.g.: Is it necessary to smoke to be cool? • Is the cause sufficient to produce the effect? • E.g.: Is wearing trendy clothes sufficient to be cool? • E.g.: Is looking tanned or muscular synonymous with being physically fit? • Are there alternative causal explanations • Are there cumulative (additional, contributory) causes? • Are there countervailing causes?