Science and Psychology

1. Science and Psychology Psych 395 - DeShon

2. Card Selection Task (Wason,1966) • 4 Cards (letter/number) • Rule: • If a card has a vowel on one side, then it has an even number on the other side • Which card or cards do you have to flip to determine whether the rule is violated? E K 4 7

3. Answer • Pick These Cards: E 7

4. Let’s get a little symbolic • If a card has a vowel on one side, then it has an even number on the other side • If P then Q • Becomes a problem in deductive logic…

5. Answers • Flip E card: If P then Q means…if P then Q. (Modus Ponens) • Flip 7 card: If P then Q means…if not Q then not P. (Modus Tollens) • Flip K card: Error – Irrelevant to Argument • Flip 4 card: Error – Rule doesn’t say that Q cannot occur in the absence of P. • Only About 10% of participants opt for both E and 7.

6. Implication • Humans are not naturally good at all aspects of formal logic. (Scientists included) • Scientific methods exist to prevent scientists from deceiving themselves (e.g., Levine & Parkinson, 1994). • The nature of Science is the focus of today’s lecture • But first an aside on the subjectivity of science…

7. Popper (1968, p. 51) • “There is no more rational procedure than the method of trial and error – of conjecture and refutation: of boldly proposing theories; of trying our best to show that these are erroneous; and of accepting them tentatively if our critical efforts are unsuccessful.”

8. Deductive Reasoning and Scientific Reasoning

9. Deductively Valid Arguments • Definition: Arguments where the truth of the premises guarantees the truth of the conclusion. • Consider Two Forms: • Modus Ponens (Mode that Affirms) • Modus Tollens (Mode that Denies)

10. Modus Ponens • Formally: • Premise 1: If P then Q. • Premise 2: P • Conclusion: Therefore, Q • In words: • If an animal is pig then the animal oinks. • Wilber is a pig. • Therefore, Wilber oinks.

11. Modus Tollens • Formally: • Premise 1: If P then Q. • Premise 2: Not Q • Conclusion: Therefore, not P • In words: • If an animal is pig then the animal oinks. • Wilber does not oink. • Therefore, Wilber is not a pig.

12. Is This How It Works in Science? • Theory: All pigs oink. • Make some observations about a newly discovered species. • Observe Q - These animals oink. • Conclude that P is True. These new animals are pigs.

13. Fallacy of Affirming the Consequent • In reality, other animals besides pigs may also oink! • So this method of reasoning is not a path to scientific progress. • Basic Idea: We CANNOT prove that scientific theories are TRUE. (Sir Karl Popper) • Scientific Reasoning is Not About Confirmation. Science is about Refutation.

14. Scientific Reasoning - Refutation • We can show that the consequence of a theory are not empirically supported. Modus Tollens. • According to Popper, falsification is the line of demarcation between science and non-science. • If we observe “Not Q” then we can conclude that P is False. • If the new animals don’t oink then they are not pigs.

15. Sounds Easy Enough, But… • No theory is tested in Isolation (Duhem-Quine Thesis) • There are lots of auxiliary theories involved in conducting a scientific study. • For example, we assume that our instruments are good indicators of the constructs under investigation. • This is why we spend so much time on measurement in 395. • We don’t know what we have precisely falsified when we observe “NOT Q” – the Big P theory or one of the auxiliary theories.

16. Fundamental Inferences Indicator of IV Indicator of DV (Observed Relation) IV Construct DV Construct (Real Relation)

17. Example • Strain Theory in Sociology (Merton, 1938) – Social Strain Produces Crime. • Possible Prediction: Blocked Opportunities should Correlate with Crime. • Observation: Perceptions of blocked Opportunities are not correlated with arrest records. • What do we conclude?

18. Fundamental Inferences Self-Reports of Blocked Opps Official Arrests (Observed) Strain Crime (Positive Relation)

19. Deduction Prediction from Theory Revision of Theory Error! Findings Induction Feedback Loop Modified from Figure 2A in Box (1976, p. 791).

20. Separate Justification from Criticism (e.g., Bartley, 1984) • Searching for complete justification is not going to get us very far. • Instead, let’s acknowledge that there is a continuum from speculation to well-established knowledge. • Argue about the reasonableness and degree of empirical support for particular propositions.

21. For Psychological Researchers… • Specify models, test models, revise models… • Researchers must be transparent so that their work can be subject to maximum criticism. • Full disclose of what was done and what was found. Accuracy and clarity are paramount virtues in the reporting of psychological research. • Hence, good writing is important.

22. Further Thoughts on Science and Models

23. Just a Few Reasons Why Psychology is Hard (e.g., Lykken, 1991; Meehl, 1978) • Everybody is an armchair psychologist. This provides resistance to simplification. • Experimental control is difficult. • Psychology seeks to understand one of the most complicated “machines” in the known universe – human brains which give rise to thoughts, feelings, and behaviors.

24. Pragmatic Viewpoint • “Every scientist in the back of [her] mind takes it for granted that even the best theory is likely to be an approximation to the true state of affairs” • Paul Meehl (1990, p. 113) • “Models, of course, are never true, but fortunately it is only necessary that they be useful. For this it is usually needful only that they not be grossly wrong.” • George E. P. Box (1979, p. 2)

25. More Thoughts on Models… • “The great advantage of the model-based approach over the ad hoc approach, it seems to me, is that at any given time we know what we are doing.” (Box, 1979, p.2) • Since all models are wrong the scientist must be alert to what is importantly wrong. It is inappropriate to be concerned with mice when there are tigers [around]. (Box, 1976, p. 792).

26. What to Do… • Appreciate how science really operates. • Favor theories that make risky predictions and survive rigorous test of those theories (e.g., Meehl, 1978, 1990). • Think Beyond One Study to Multiple Studies -- Focus on Replication (Lykken, 1968)

27. Importance of Replication • Scientists have known for centuries that a single study will not resolve a major issue. Indeed, a small sample study will not even resolve a minor issue. Thus, the foundation of science is the culmination of knowledge from the results of many studies. • Source: Hunter, Schmidt, & Jackson (1982, p. 10)

28. Causality

29. Science vs. Societal Values • The history of science reflects a clash between what we currently believe to be true and the new “truths” we discover about the world. • Virtually everything we once “knew to be true” has been shown to be false. • Magic • Geocentric models of the universe • Flat earth • Medicine (blood letting, arsenic, etc.) • Newtonian Physics?

30. Example: Rind et al (1998) • Societal Belief: Child Sexual Abuse is wrong and causes substantial harm and results in negative outcomes in adults. • Rind et al (1998) performed a meta-analysis (a statistical summary) of the existing literature and did not find support for the claim that CSA results in substantial negative long-term outcomes in adults • < 1% of variance in outcomes

31. Huge public and political response • Lilienfeld (2002) documents the response • Nearly caused the downfall of the APA • Dr. Laura condemned the research • Religious groups united against the research • Politicians with no scientific training began criticizing the study • APA caved to political and public pressure and renounced the study

32. Aftermath • Public policy review initiated at APA • Congress voted 355 to 0 to condemn and denounce the findings • Senate passed the resolution the same month • Scientific review panels found no serious fault with the study • Highlights a huge gap between popular press and academic science

33. Some Terminology • Variables: Any attribute that changes values across things that are being studied. • Hypothesis: A testable statement describing the relation between two or more constructs. • Constructs: Abstract qualities that we attempt to measure. • Operational Definition: Statement of the process we use to measure constructs. • Constructs  Actual Measures in a given study

34. Operational Definitions • Going from the Unobserved to the Observed… Measured Variables x y X Y Unobservable Constructs

35. Scientific Approach to Causation • “Development of Western science is based on two great achievements: the invention of the formal logical system (in Euclidean geometry) by the Greek philosophers, and the discovery of the possibility to find out causal relationships by systematicexperiment (during the Renaissance).” • Albert Einstein (1953)

36. Causal Relations • John Stuart Mill (1806-1873) • Three Conditions for Cause and Effect Relations. • Temporal Ordering (Cause Preceded the Effect) • Covariation (Cause and Effect are Associated) • Rule Out Third Variables (No Plausible Explanation for the Effect Other than the Cause)

37. Newton’s 4 Rules of Scientific Reasoning (Principia, 1680) • Admit no more causes of things than are both true and sufficient to explain their appearance. • Occam’s razor • Rule of Parsimony • Sherlock Holmes • The simplest theory that fits the facts of a problem is the one that should be selected. Example: Geocentric view of solar system Example: Crop circles

38. Newton’s 4 rules • To the same natural effects we must, as far as possible, assign the same causes. • Generality • Example: Gravity and falling objects • The qualities of bodies which are found to belong to all bodies within the reach of experimentation should be assumed to be universal qualities of all bodies • Generalization • Example: Gravity on other planets

39. Newton’s 4 rules • Theories obtained from experiments should be considered true until new experimental evidence shows the old to be incorrect. • Values should not lead to changes in theories • The history of science represents a continuous struggle between existing values and empirical data (new and old beliefs)

40. Experimental Approach to Studying Causal Relations • Intervention, Observation, and Control • Random assignment of participants to two or more conditions of an experiment. • The Independent variable is the variable that is manipulated or the experimental conditions (e.g., treatment or no-treatment). • The Dependent variable is the outcome of interest in the particular study.

41. Where do research ideas come from? • Observe your world! • Why do some people work so hard? • Do social systems function like ant colonies? • Why is karaoke so popular? • Why do people sacrifice long term gain for short term pleasure (delay of gratification)? • What is boredom? • What do individuals get out of belonging to a counter-culture? • Why do people collect stuff? • Ask questions about your own behavior! • Why did I do that?

42. Bathroom Behavior Personal Space Invasion in the Lavatory: Suggestive Evidence for Arousal - Middlemist et al. (1976)

43. Invasions of Privacy are Bad • Do Space Violations Cause Arousal? • Theory: Space Violations  Arousal  Responses to Personal Space Violation • Where can we study personal space violations?

44. The Men’s Room….

45. Let’s Put this in Scientific Terms… • “Urinals are open and placed side by side so that, under crowded conditions, men stand shoulder to shoulder, coactively engaging in private elimination” (Middlemist et al., 1976, p. 542) • Conducted research on micturation – “a process sensitive to arousal” • “Fright and embarrassment inhibited relaxation of the external sphincter of the urethra” (Middlemist et al., 1976, p. 542)

46. Hypothesis (Middlemist, et al., p. 542) • “If personal space invasions produce arousal, then subjects standing closest to others … would show increases in the delay of onset of micturation and decreases in the persistence of micturation” • Translation:

47. Design • 60 Men randomly assigned to one of three conditions: • Close Distance (16 to 18 inches) • Moderate Distance (52 to 54 inches) • Control (Peeing Solo) • An observer hides in toilet stall and makes a “direct visual sighting of the stream of urine” • “Subjects were not informed that they had participated in an experiment”

48. Close Distance Condition

49. Moderate Distance

50. Results – Delay of Micturation