1. Myers’ PSYCHOLOGY (7th Ed) Chapter 1 Thinking Critically with Psychological Science James A. McCubbin, PhD Clemson University Worth Publishers

2. The Need for Psychological Science Psychologists, like all scientists, use the scientific method to construct theories that organize observations and imply testable hypotheses

3. The Need for Psychological Science  Hindsight Bias  we tend to believe, after learning an outcome, that we would have foreseen it  the “I-knew-it-all-along” phenomenon  Overconfidence  we tend to think we know more than we do

4. The Need for Psychological Science  Critical Thinking  thinking that does not blindly accept arguments and conclusions  examines assumptions  discerns hidden values  evaluates evidence The Amazing Randi--Skeptic

5. The Need for Psychological Science  Theory  an explanation using an integrated set of principles that organizes and predicts observations  Hypothesis  a testable prediction  often implied by a theory

6. The Need for Psychological Science

7.  Operational Definition  a statement of procedures (operations) used to define research variables  Example-  intelligence may be operationally defined as what an intelligence test measures

8. The Need for Psychological Science  Replication  repeating the essence of a research study to see whether the basic finding generalizes to other participants and circumstances  usually with different participants in different situations

9. Description Psychologists describe behavior using case studies, surveys, and naturalistic observation

10. Description Case Study  Psychologists study one or more individuals in great depth in the hope of revealing things true of us all Is language uniquely human?

11. Description  Survey  technique for ascertaining the self-reported attitudes or behaviors of people  usually by questioning a representative, random sample of people  Random Sample  a sample that fairly represents a population because each member has an equal chance of inclusion

12. Description  False Consensus Effect  tendency to overestimate the extent to which others share our beliefs and behaviors  Population  all the cases in a group, from which samples may be drawn for a study

13. Description

14.  If marbles of two colors are mixed well in the large jar, the fastest way to know their ratio is to blindly transfer a few into a smaller one and count them

15. Description  Naturalistic Observation  observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

16. CORRELATIONAL zExpresses a relationship between two variables without implying causation zPositive correlation—the presence of one thing predicts the presence of the other zNegative correlation—the presence of one thing predicts the absence of the other

17. Correlation  Correlation Coefficient  a statistical measure of the extent to which two factors vary together, and thus how well either factor predicts the other  Does not imply causation Correlation coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = +.37

18. Correlation  Scatterplot  a graphed cluster of dots, each of which represents the values of two variables  the slope of the points suggests the direction of the relationship  the amount of scatter suggests the strength of the correlation  little scatter indicates high correlation  also called a scattergram or scatter diagram

19. Correlation Perfect positive correlation (+1.00) No relationship (0.00)Perfect negative correlation (-1.00) Scatterplots, showing patterns of correlations

20. Correlation Height and Temperament of 20 Men 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 80 63 61 79 74 69 62 75 77 60 64 76 71 66 73 70 63 71 68 70 75 66 60 90 60 42 60 81 39 48 69 72 57 63 75 30 57 84 39 Subject Height in Inches Temperament Subject Height in Inches Temperament

21. Correlation Scatterplot of Height and Temperament 55 60 65 70 75 80 85 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 Temperament scores Height in inches

22. Correlation Three Possible Cause-Effect Relationships (1) Low self-esteem Depression (2) Depression Low self-esteem Depression (3) Distressing events or biological predisposition could cause or and

23. Illusory Correlation  Illusory Correlation  the perception of a relationship where none exists ConceiveDo not conceive Adopt Do not adopt disconfirming evidence confirming evidence disconfirming evidence confirming evidence

24. Two Random Sequences  Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.

25. Experimentation  Experiment  an investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)  by random assignment of participants the experiment controls other relevant factors

26. Experimentation  Placebo  an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent  Double-blind Procedure  both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo  commonly used in drug-evaluation studies

27. Experimentation  Experimental Condition/group  the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable  Control Condition/group  the condition of an experiment that contrasts with the experimental treatment  serves as a comparison for evaluating the effect of the treatment

28. Experimentation  Random Assignment  assigning participants to experimental and control conditions by chance  minimizes pre-existing differences between those assigned to the different groups

29. Experimentation  Independent Variable  the experimental factor that is manipulated  the variable whose effect is being studied  Dependent Variable  the experimental factor that may change in response to manipulations of the independent variable  in psychology it is usually a behavior or mental process

30. Experimentation

31. Research Strategies  Design of the subliminal tapes experiment Subliminal tape content Self-esteemMemory Self-esteem Tape label

32. Statistical Reasoning Our Brand Brand Brand Brand X Y Z 100% 99 98 97 96 95 Percentage still functioning after 10 years Brand of truck

33. Statistical Reasoning Our Brand Brand Brand Brand X Y Z 100% 90 80 70 60 50 40 30 20 10 0 Percentage still functioning after 10 years Brand of truck

34. Statistical Reasoning  Mode  the most frequently occurring score in a distribution  Mean  the arithmetic average of a distribution  obtained by adding the scores and then dividing by the number of scores  Median  the middle score in a distribution  half the scores are above it and half are below it

35. Skewed Distribution zWhen a distribution includes an extreme score (or group of scores) that is very high, the distribution is said to be Positively skewed. zWhen a distribution includes an extreme score (or group of scores) that are very low, the distribution is said to be negatively skewed.

36. Statistical Reasoning A Skewed Distribution 15 20 25 30 35 40 45 50 90 475710 70 Mode Median Mean One Family Income per family in thousands of dollars

37. Variations

38. Statistical Reasoning  Range  the difference between the highest and lowest scores in a distribution  Standard Deviation  a computed measure of how much scores vary around the mean  Statistical Significance  a statistical statement of how likely it is that an obtained result occurred by chance

39. Bell shaped curve zZ scores—measure the distance of a score from the mean in units of standard deviation zScores below mean have negative z scores zScores above mean have positive z scores zEx: Allison scored a 130 on an IQ test with a mean of 100 and a standard deviation of 15. What is her z score? zEx: Juan scored an 85 on the same IQ test. What is his z score?

40. Try it yourself zIf Scott scored a 72 on a test with a mean of 80 and a standard deviation of 8. What is his z score? zIf Diamond scored an 84 on the same test. What is her z score?

41. Ethics in Psychology zEthical guidelines are established by the APA (American Psychological Association) zGuidelines are set for animal & human research zAny type of academic research first has to propose the study to the ethics board IRB (Institutional Review Board) at the institution

42. Animal Research Requirements zThey must have a clear scientific purpose zResearch must answer a specific scientific question zAnimals chosen must be the best suited to answer the question zMust care and house animals in humane way zMust acquire animal subjects legally zExperimental procedures must employ least amount of suffering as possible.

43. Human Research Requirements zNo coercion—participation is voluntary zInformed consent zAnonymity or confidentiality—name is not associated with any responses zNo high long term risk—physical or mental zDebriefing—participants told what study was for and how to get the results

44. Frequently Asked Questions about Psychology Can laboratory experiments illuminate everyday life?

45. Frequently Asked Questions about Psychology Does behavior depend on ones culture?  Culture--the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next

46. Frequently Asked Questions about Psychology Does behavior vary with gender?

47. Frequently Asked Questions about Psychology Why do psychologists study animals? Is it ethical to experiment on animals? Is it ethical to experiment on people?

48. Frequently Asked Questions about Psychology Is psychology free of value judgments?

49. Frequently Asked Questions about Psychology Is psychology potentially dangerous?