1. Chapter 1 Critically Thinking with Psychological Science
The Need for Psychological Science
The limits of Intuition and Common Sense
Questions and answers with the
Scientific Method
The Scientific Attitude
Statistical Reasoning (descriptive statistics)

2. Impression of Psychology
Many people listen to talk-radio counselors and psychics Who to take seriously? People tend to be interested in magic, and the mystical.
Dr. Crane (radio-shrink)
Psychic (Ball gazing)

3. The Need for Psychological Science as well as Intuition & Common Sense
Is intuition and common sense are good enough? In many cases this is correct.
Although intuitions and common sense may aid queries, they are not free of error.
Hindsight bias: I knew all along the picture was fake. I was quite sure (overconfident).
Psychology 7e in Modules

4. Errors of Common Sense: a form of bias
Try this !
If you were to fold
a piece of paper (0.1 mm thick) a 100 fold,
how large do you think its thickness would be?
800,000,000,000,000 times the distance between the sun and the earth.
Psychology 7e in Modules

5. Hindsight Bias Hindsight Bias is the “I-knew-it-all-along” phenomenon.
We tend to believe, after learning about an outcome, that we would have foreseen it. We knew that the dot.com stocks would plummet, only after they did.
Birds of a feather flock together.
Opposites attract.
OBJECTIVE 1| Describe hindsight bias and explain how it can make research findings seem like mere common sense.
“Anything seems commonplace, once explained.” Dr. Watson to Sherlock Holmes.
Two phenomena – hindsight bias and judgmental overconfidence – illustrate why we cannot rely solely on intuition and common sense.
Psychology 7e in Modules

6. Bias: Overconfidence
We tend to think we know more than we actually do.
Anagram
How long do you think would it take to unscramble these anagrams?
WREAT
WATER
ETYRN
ENTRY
People said about 10 seconds. On average they took about 3 minutes (Goranson, 1978).
OBJECTIVE 2| Describe how overconfidence contaminates our everyday judgments.
GRABE
BARGE
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7. Bias: Order in Random Events
Given random data we look for order, for meaningful patterns.
Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
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8. Lies, more lies and then there are statistics
Meaningful non- deceptive description of data is important in research.
Misrepresentation can lead to incorrect conclusions.
OBJECTIVE 16| Explain how graphs can misrepresent data.
Psychology 7e in Modules

10. Michael Shermer Two different ways to believe, neither is wrong:
Belief based on faith.
Belief based on empirical data.
Know the difference.

13. Critical Thinking
Scientific thinking does not “blindly” accept arguments and conclusions. Evidence is needed.
Science examines assumptions, discerns hidden values, evaluates evidence, assesses conclusions.
Courtesy of the James Randi Education Foundation
The Amazing Randi

14. The Scientific Attitude
The scientific attitude is composed of
curiosity (passion for exploration),
healthy skepticism (doubting and questioning) and humility (humbleness to accept when wrong).
OBJECTIVE 3| Explain how the scientific attitude encourages critical thinking.
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15. Bias: Is psychological study free of value judgments?
No. Psychology emerges from people who subscribe to a set of values and judgments.
OBJECTIVE 24| Describe how personal values can influence psychologists’ research and its application, and discuss psychology’s potential to manipulate people.
© Roger Shepard
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16. Scientific Method…
Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.
Curious: a question or concern
Research about the topic.. Library internet, valid sources?
Found satisfactory answer? DONE!
But, you still have questions, or are otherwise unsatisfied with the answers or finding.
Conduct your own study based on current theory and use a hypothesis.
OBJECTIVE 4| Describe how psychological theories guide scientific research.
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17. Theories and hypotheses
Theory is an explanation that integrates principles, organizes and predicts behaviors or events.
For example, low self-esteem is correlated to depression.
Hypothesis is a testable prediction, often induced by a theory, to enable us to accept, reject or revise the theory.
People with low self-esteem have lower scores on Beck’s depression scale.
Three genres of hypotheses
1. Descriptive 2. Experimental 3. Correlational
If we were to observe that depressed people talk about their past, present, and future in a gloomy manner, we may theorize that low-self-esteem contributes to depression.
Psychology 7e in Modules

18. Scientific Method… . 11. Start again! 6. Design basic type of study
Descriptive, correlational or causational?
7. Consider: approval, ethics, sampling, where to conduct the study, who is in the study, operational definitions, methods, materials to use, how to proceed…
8. Carry out study and analyze data with statistics.
9. Was the hypothesis (questions) supported or deemed false?
10. Share your results!
11. Start again! .

19. Reliability and validity
Operational definitions
Define aggressive. How to measure it?
Measuring
Self-report
Observing and tracking
Machines

20. Reliability and validity: Random Sampling: recruiting participants
In a population, if each member has an equal chance of inclusion into a sample, we call that a random sample (unbiased).
Very few true random samples
in Psychology.
Lots of college students and rats.
Case studies: individual or few subjects

21. Reliability and validity: Survey
Wording can change the results of a survey.
Should cigarette ads and pornography be forbidden on television? (not allowed vs. forbid; and “double-barreled”)
Which of the following is your favorite genre of movie: Westerns, Romance or Science Fiction?

22. Ethics: Treatment of Participants
Animals (many fewer used today)
Do no or little harm
Value of research in proportion to what happens to animal
Study must Pass IRB
People
Informed Consent
Do no (little) harm mental or physical
May quit at anytime
Value of research in proportion to what happens to person
Study must pass IRB

23. Who and how: Naturalistic Observation and Lab studies
Observing and recording behavior of animals in the wild, public behavior (e.g. bathrooms) …to recording self-seating patterns in lunch rooms in a multiracial school constitutes naturalistic observation.
How “fake” is the lab setting?
OBJECTIVE 7| Identify the advantages and disadvantages of naturalistic observation in studying behavior and mental processes.
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24. Control of bias Double-blind Procedure
It important to keep the participants and experimenter’s assistants blind to which participants got real treatment and which got a placebo.
Particularly useful in drug studies.
OBJECTIVE 13| Explain why random assignment and double-blind procedure build confidence in research findings.
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25. Types of Research and statistics
1. Descriptive: a series of single numbers
2. Experimental: Exploring Cause and Effect
3. Correlational: Relationship but NOT Causation
Improves predictability
Illusory Correlation
Perceiving Order in Random Events

26. Description: Measures of Central Tendency (clustering)
Mode: The most frequently occurring score in a distribution.
Mean: The arithmetic average of scores in a distribution obtained by adding the scores and then dividing by their number.
Median: The middle score in a rank-ordered (low to high) distribution.
Draw a few pictures!
OBJECTIVE 17| Describe three measures of central tendency and tell which is most affected by extreme scores.
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27. Measures of Central Tendency
A Skewed Distribution

28. Description: Measures of Variation (spread out)
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.
OBJECTIVE 18| Explain two measures of variation.
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29. Standard Deviation: aaaccckkkk Do not need to know formula for test~

30. Now to look at Experimentation: Exploring Cause and Effect
Experiments attempt to
isolate causes (IV) and their effects (DV).
Important considerations:
Random sampling
Independent variable (IV)
- levels/conditions of the IV kept “equal”
- random assignment: “the great equalizer”
Dependent Variables (DV)
Control of Bias (placebo/blind/extraneous)
OBJECTIVE 12| Explain how experiments help researchers isolate cause and effect.
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31. Independent Variable Random selection vs. Random Assignment Room
Independent Variable is a factor, manipulated by the experimenter, and whose effect is being studied.
It is separated into comparison “conditions, levels, groups.” which except for the IV are as identical as possible
While a true Control group isn’t always needed, some comparison group is.
Control factors
Random selection vs. Random Assignment
Room
Materials
Time of day
Outside noise
… a million things!
OBJECTIVE 14| Explain the difference between an independent variable and a dependent variable.
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32. Dependent Variable
Dependent Variable is a factor that may change in response to independent variable. It is what is being measured.
In psychology it is usually a behavior or a mental process.
Control factors: define and measure carefully
Is there a cause? Running the numbers/statistics
When the averages are farther apart and the data do not overlap too much.
Draw pictures on the board.

33. Correlation = relationship Correlation isn’t set up to find a cause
When one variable can be predicted better based on knowing about another variable. or
OBJECTIVE 9| Explain why correlational research fails to provide evidence of cause-effect relationships.
Real correlation but meaningless: Hemlines and the stock market.
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34. Correlations: direction and strength
When one variable can be predicted better based on knowing about another variable.
Indicates strength
of relationship
(0.00 to 1.00)
Correlation
coefficient
r = +
0.37
OBJECTIVE 8| Describe positive and negative correlations and explain how correlational measures can aid the process of prediction.
Correlation Coefficient is a statistical measure of relationship between two variables.
Indicates direction
of relationship
(positive or negative)
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35. A Scatterplot showing a positive relationship between height and temperament in people (with a moderate positive correlation of +0.63).
A perfect positive 1-1 match up: never really happens

36. From perfect to perfect: +1.00 to -1.00

37. The end

38. Bias: False Consensus Effect
A tendency to overestimate the extent
to which others share our beliefs and behaviors.
“yes, we are all individuals”

39. Is language uniquely human?
Who and how
Case Study
A technique in which one person (or very few) is studied in depth to reveal underlying behavioral principles.
OBJECTIVE 5| Identify the advantages and disadvantages of case studies in studying behavior and mental processes.
Susan Kuklin/ Photo Researchers
Is language uniquely human?
Psychology 7e in Modules

40. Gathering DATA The Survey
A self-report
about attitudes, opinions or behaviors of people.
OBJECTIVE 6| Identify the advantages and disadvantages of surveys in studying behavior and mental processes, and explain the importance of wording effects and random sampling.
Psychology 7e in Modules

41. Disconfirming evidence
Illusory Correlation
The perception of a relationship where none exists. Parents conceive children after adoption.
Confirming evidence
Disconfirming evidence
Do not
adopt
Adopt
Do not conceive
Conceive
OBJECTIVE 10| Describe how people form illusory correlations.
Michael Newman Jr./ Photo Edit
Psychology 7e in Modules

42. Scatterplots
Perfect positive
correlation (+1.00)
Scatterplot is a graph that comprises of points generated by values of two variables. The slope of points depicts the direction, and the amount of scatter the strength of relationship.

43. Scatterplots
Perfect negative
correlation (-1.00)
No relationship (0.00)
Scatterplot on the left shows a negative correlation, and the one on the right shows no relationship between the two variables.

44. Q5. Is it ethical to experiment on animals?
FAQ
Q5. Is it ethical to experiment on animals?
Ans: Yes. To gain insights to devastating and fatal diseases. All researchers who deal with animal research are required to follow ethical guidelines in caring for these animals.

45. Q6. Is it ethical to experiment on people?
FAQ
Q6. Is it ethical to experiment on people?
Ans: Yes. Experiments that do not involve any kind of physical or psychological harm that is beyond normal levels encountered in daily life can be carried out.

46. Q8. Is psychology potentially dangerous?
FAQ
Q8. Is psychology potentially dangerous?
Ans: It can be, but it is not. The purpose of psychology is to help humanity with its problems, like war, hunger, prejudice, crime, family dysfunction, etc.

47. Q1. Can laboratory experiments illuminate everyday life?
FAQ
Q1. Can laboratory experiments illuminate everyday life?
Ans: Artificial laboratory conditions are created to study behavior in simplistic terms. The goal is to find underlying principles that govern behavior.
OBJECTIVE 21| Explain the value of simplified laboratory conditions in discovering general principles of behavior.
Psychology 7e in Modules

48. Below is a comparison of different research methods.

49. Order in Random Events
Given large number of random outcomes, a few are likely to express order.
Jerry Telfer/ San Francisco Chronicle
OBJECTIVE 11| Explain the human tendency to perceive order in random events.
Angelo and Maria Gallina won two California lottery games on the same day.
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50. Q2. Does behavior depend on one’s culture?
FAQ
Q2. Does behavior depend on one’s culture?
Ans: Even when specific attitudes and behaviors vary across cultures, as they often do, the underlying processes are much the same.
OBJECTIVE 22| Discuss whether psychological research can be generalized across cultures and genders.
Ami Vitale/ Getty Images
Psychology 7e in Modules

51. Q3. Does behavior vary with gender?
FAQ
Q3. Does behavior vary with gender?
Ans: Yes. Biology determines our sex, and then culture further bends the genders. Yet in many ways woman and man are similarly human.

52. Q4. Why do psychologists study animals?
FAQ
Q4. Why do psychologists study animals?
Ans: Study of animals gives us the understanding of many behaviors that may have common biology across animals and humans.
OBJECTIVE 23| Explain why psychologists study animals, and discuss the ethics of experimentation with both animals and humans.
D. Shapiro, © Wildlife Conservation Society
Psychology 7e in Modules