2 Thinking Critically with Psychological Science Chapter 1
3 The Need for Psychological Science Intuition & Common Sense Many people believe that intuition and common sense are enough to bring forth answers regarding human nature. Intuition and common sense may aid queries, but they are not free of error.
5 Limits of Intuition Personal interviewers may rely too much on their “gut feelings” when meeting with job applicants. Taxi/ Getty Images
6 Hindsight Bias is the “I-knew-it-all-along” phenomenon. After learning the outcome of an event, many people believe they could have predicted that very outcome. We only knew the dot.com stocks would plummet after they actually did plummet. Hindsight Bias
Overconfidence Activity I feel 98 percent certain that the area of the U.S. is more than ____ square miles but less than ____ square miles. I feel 98 percent certain that in 2003 the population of Australia was more than ___ but less than ____. I feel 98 percent certain that the number of American battle deaths in the Spanish-American War was more than ___ but less than ___. 7
Overconfidence Activity I feel 98 percent certain that in 2002 the number of female engineers in the United States was more than ___ but less than ___. I feel 98 percent certain that in 2002 the number of operating nuclear plants in the world was more than ___ but less than ___. 8
9 Overconfidence Sometimes we think we know more than we actually know. Anagram BARGEGRABE ENTRYETYRN WATERWREAT How long do you think it would take to unscramble these anagrams? People said it would take about 10 seconds, yet on average they took about 3 minutes (Goranson, 1978).
10 Overconfidence Anagram ELEPHANTLPNTEEAH CIRCUSICSCRU CHAOSOCHSA Now try this word scramble!
11 The Point to Remember Hindsight bias and overconfidence often lead us to overestimate our intuition. But scientific inquiry, fed by curious skepticism and by humility can help us sift reality from illusions.
12 Psychological Science 1.How can we differentiate between uniformed opinions and examined conclusions? 2.The science of psychology helps make these examined conclusions, which leads to our understanding of how people feel, think, and act as they do!
13 The Scientific Attitude The scientific attitude is composed of curiosity (passion for exploration), skepticism (doubting and questioning) and humility (ability to accept responsibility when wrong).
14 Critical Thinking Critical thinking does not accept arguments and conclusions blindly. It examines assumptions, discerns hidden values, evaluates evidence and assesses conclusions. The Amazing Randi Courtesy of the James Randi Education Foundation
15 Scientific Method Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.
16 VIDEO DISCOVERING PSYCHOLOGY: RESEARCH METHODS Video link: http://www.learner.org/discoveringpsychology/02/e02expand.htmlhttp://www.learner.org/discoveringpsychology/02/e02expand.html
17 A Theory is an explanation that integrates principles and organizes and predicts behavior or events. For example, low self-esteem contributes to depression. Theories are NOT the product of guesswork! They are highly researched, rigorously tested frameworks. Theory
TROUBLESHOOTING NOTE: Our text does not use the term generalizability. This term is used on the AP EXAM. It refers to what degree the results of a study can be applied to different types of populations. 18
19 A Hypothesis is a testable prediction, often prompted by a theory, to enable us to accept, reject or revise the theory. People with low self-esteem are apt to feel more depressed. TROUBLESHOOTING: A hypothesis is NOT an educated guess. Hypothesis
HYPOTHESIS In psychology, a hypothesis is a statement of a relationship between or among variables. (not in text) 20
21 Research would require us to administer tests of self-esteem and depression. Individuals who score low on a self-esteem test and high on a depression test would confirm our hypothesis. Research Observations
23 Operational Definitions To reduce bias psychologists report their research with operational definitions. An operational definition states how the variable is observed and measured. An operational definition must be manageable. Operational definitions allows others to replicate (repeat) the observations. Why?
24 OPERATIONAL DEFINTIONS ACTIVITY Determine an operational definition for each underlined variable. Remember an operational definition is observable and measurable.
25 Operational Definitions: The teacher wants to find a way to help make Billy act more friendly toward other children. A psychologist wants to know if the new form of psychotherapy will make people less depressed. A student wants to find a way to study more efficiently. Does this drug help people overcome tiredness? Boys show more affection for their fathers than their mothers. People dream more if they have a big meal before going to sleep. College athletes are not as smart as regular students. Overall senior girls are prettier than sophomore girls. How does grade point average affect a person’s sense of humor? People who make over $100,000 a year tend to be snobs.
26 TO TEST A HYPOTHESIS Make an observation Describe the behavior Detect correlations that predict the behavior Design research Develop a hypothesis about North Penn student behavior. The hypothesis should have variables that can be operationally defined.
HYPOTHESIS Replication is the main goal of all good research. Replication allows researchers to test hypotheses with other samples from other populations so that results can be generalized. 27
28 Description: Starting point of any science. Case Study A technique in which one person, group, or situation is studied in depth to reveal underlying behavioral principles. Is language uniquely human? Susan Kuklin/ Photo Researchers
29 CASE STUDY Long tradition in clinical work, Freud’s theory of psychoanalysis Can include tests, interviews, analysis of letters, or transcripts
30 CASE STUDY EXAMPLES: Freud, Piaget, chimp studies, Phineas Gage Advantages: –Depth of information –Appropriate for new, rare, or complex cases, Disadvantages: –Individual may be atypical or unrepresentative –Anecdotal information can overwhelm general truths
31 Case Study A clinical study is a form of case study in which the therapist investigates the problems associated with a client. Example: Oliver Sack’s “The Man Who Mistook His Wife for his Hat” http://behavioralhealth.typepad.com Clinical Study
32 Survey A technique for ascertaining the self-reported attitudes, opinions or behaviors of people usually done by questioning a representative, random sample of people. http://www.lynnefeatherstone.org
TROUBLESHOOTING: A random sample typically generates a representative sample. Random assignment involves taking a randomly chosen sample and assigning the participants at random to either the experimental or control group of an experiment. (only used in experiments) 33
34 SURVEY Use interviews or questionnaires to ask about behavior, attitudes, opinions, beliefs, or intentions
35 Survey Wording can change the results of a survey and thus affect validity. Q: Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid) Wording Effect
36 WORDING EFFECTS The Statistical Assessment Service nominated the following 1937 British Gallup Poll question as a leading candidate for the “Worst Poll Question of All Time”. “Are you in favor of direct retaliatory measures against Franco’s piracy?” Why? Modern example?
37 PROBLEMS WITH QUESTION 1. It is not balanced. 2. It assumes knowledge 3. It does not use everyday language. 4. It employs a perjorative. 5. It is vague
38 WORDING EFFECTS Women with young children should be able to work outside the home. –8 in 10 Americans agreed
39 WORDING EFFECTS Women should stay at home if they have young preschool children. 7 in 10 Americans agreed
40 WORDING EFFECTS The problems faced by blacks have been brought on by blacks themselves
41 With a white interviewer: 62% of whites agreed With a black interviewer: 46% of whites agreed
42 SURVEY People may be reluctant to admit undesirable or embarrassing things about themselves. Or they may say what they think they should say.. Examples
43 WORDING EFFECTS Not allowing vs forbidding More restrictions vs government censorship Aid to needy vs welfare Affirmative action vs preferential treatment
44 Survey A tendency to overestimate the extent to which others share our beliefs and behaviors. Example? False Consensus Effect
45 Survey Random Sampling If each member of a population has an equal chance of inclusion into a sample, it is called a random sample (unbiased). If the survey sample is biased, its results are not valid. Only those who want to make a point may respond The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.
46 Random Sampling Exercise Various Scenarios Basketbally Activity
47 ACTIVITY Get out of your seats. Push the seats back. You may not sit down or lean against anything.
48 Naturalistic Observation Examples: Observing and recording the behavior of animals in the wild; recording self-seating patterns in a multiracial school lunch room. Courtesy of Gilda Morelli
49 NATURALISTIC OBSERVATION Describes, does not explain Often used by ethologists such as Jane Goodall Behavior changes when you know you are being watched Observations may be distorted by what the experimenters expect to see. Other advantages, disadvantages?
50 Descriptive Methods Case studies, surveys, and naturalistic observation describe behaviors. Summary
51 CORRELATION Correlation = relationship between variables Variables = the specific factors or characteristics that are manipulated and measured in research Evidence should be evaluated in terms of reliability and validity Reliability: repeatable (replication) Validity: accurately assesses topic
52 CORRELATION Scatterplots: represent the values of two variables; indicates correlation or relationship between the variables Measured by the correlation coefficient, a statistical measure of relationship. The extent to which two factors vary together, and thus of how well either factor predicts the other.
53 Perfect positive correlation (+1.00) Scatterplot is a graph comprised of points that are generated by values of two variables. The slope of the points depicts the direction, while the amount of scatter depicts the strength of the relationship. Scatterplots
54 No relationship (0.00) Perfect negative correlation (-1.00) The Scatterplot on the left shows a negative correlation, while the one on the right shows no relationship between the two variables. Scatterplots
55 Data Data showing height and temperament in people.
56 Scatterplot The Scatterplot below shows the relationship between height and temperament in people. There is a moderate positive correlation of +0.63.
57 CORRELATION POSITIVE CORRELATION: A direct relationship. Two variables increase or decrease together. NEGATIVE CORRELATION: An inverse relationship. As one variable increases, the other decreases.
58 Correlation When one trait or behavior accompanies another, we say the two correlate. Correlation coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = 0.37 + Correlation Coefficient is a statistical measure of the relationship between two variables.
59 CORRELATION Strength of the relationship is indicated by the number. –The closer it is to zero, the weaker the relationship –The closer it is to one (plus or minus), the stronger the relationship –Interpret: +.8, -,2, -.9, +.3
61 Illusory Correlation The perception of a relationship where no relationship actually exists. When we believe there is a relationship we are likely to notice and recall instances that confirm our belief: Parents conceive children after adoption. Confirming evidence Disconfirming evidence Do not adopt Disconfirming evidence Confirming evidence Adopt Do not conceive Conceive Michael Newman Jr./ Photo Edit
62 ILLUSORY CORRELATIONS Examples of Illusory Correlations: It always rains when … The phone always rings when… More serious implications?
63 Illusory Correlation The Point to Remember: When we notice random coincidences, we may forget that they are random and instead see them as correlated. Thus we can easily deceive ourselves by seeing what is not there. Michael Newman Jr./ Photo Edit
64 Correlation The Point To Remember: A correlation coefficient helps us see the world more clearly by revealing the extent to which two things relate.
65 Correlation and Causation Very important to remember: Correlation does necessarily prove causation!
66 Given random data, we look for order and meaningful patterns. Order in Random Events Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
67 Order in Random Events Given large numbers of random outcomes, a few are likely to express order. Angelo and Maria Gallina won two California lottery games on the same day. Jerry Telfer/ San Francisco Chronicle
69 Experimentation Like other sciences, experimentation is the backbone of psychology research. Experiments isolate causes and their effects. Exploring Cause and Effect
70 Many factors influence our behavior. Experiments (1) manipulate factors that interest us, while other factors are kept under (2) control. Effects generated by manipulated factors isolate cause and effect relationships. Exploring Cause & Effect
71 An Independent Variable is a factor manipulated by the experimenter. The effect of the independent variable is the focus of the study. For example, when examining the effects of breast feeding upon intelligence, breast feeding is the independent variable. Independent Variable
72 A Dependent Variable is a factor that may change in response to an independent variable. In psychology, it is usually a behavior or a mental process. For example, in our study on the effect of breast feeding upon intelligence, intelligence is the dependent variable. Dependent Variable
73 IV/DV Activity Identify the Independent/Dependent Variable.
74 EXPERIMENT Experimenters aim to manipulate an independent variable, measure the dependent variable, and control all other variables. When determining i.v. and d.v., think “what (IV) affects what (DV)?”” Practice exercises Reaction time experiment
75 CONTROLING OTHER VARIABLES An experiment has at least two different conditions: control condition experimental condition Random assignment of subjects between conditions equates the conditions. Basketball example.
76 Population Representative Sample ( larger the better) Experimental Group Control Group Apply Methods of Control Independent Variable Placebo Measure Dependent Variable Is the difference statistically significant? Random Assignment Everyone has equal chance. Random Sampling (aka Random Selection) This is the goal! EXPERIMENTAL DESIGN =
77 CONFOUNDING AND RANDOM VARIABLES Types of Confounding Variables: –Random Variables –Participants Expectations –Experimenter Bias These variables need to be eliminated when possible. Why? Random assignment is presumed to distribute impact of uncontrolled variables randomly and probably equally across groups.
78 OTHER METHODS OF CONTROL Eliminating confirmation bias Eliminating order effects Matching conditions to eliminate confounding variables Double blind Eliminate experimenter bias
79 Experimentation A summary of steps during experimentation.
80 EXPERIMENTATION Population (group you are generalizing your hypothesis to) Random sample from the population Random sample creates a representative sample rather than a biased sample Random assignment of subjects to experimental group or control group
81 EXPERIMENTATION Experimental group gets the independent variable Control group gets the placebo Be sure all measures of control are in place so the only thing influencing the results (dependent variable) is the independent variable
82 EXPERIMENTATION Measure the dependent variable (you can do this because of operational definitions) Compare the results between the experimental group and the control group using inferential statistics. Is there a statistically significant difference? –This means that the difference we observed is probably not due to chance variation between the samples. –Do not make much of a finding unless the odds of its occurring by chance are less than 5% (.05). If so, you have established a causal relationship.
83 Statistical Significance Criterion is usually 5% (0.05) or 1 in 20 Statistical significance indicates the likelihood that a result will happen by chance; it does not indicate importance of result.
84 Comparison Below is a comparison of different research methods.
85 Population Representative Sample ( larger the better) Experimental Group Control Group Apply Methods of Control Independent Variable Placebo Measure Dependent Variable Is the difference statistically significant? Random Assignment Everyone has equal chance. Random Sampling (aka Random Selection) This is the goal! EXPERIMENTAL DESIGN =
86 ETHICAL PRINCIPLES Established by the American Psychological Association –Obtain informed consent of potential participants –Protect subjects from harm and discomfort –Treat information about subjects confidentially –Fully explain the research afterward (debrief) –Institutional Review Boards (IRB) should screen research proposals
87 STATISTICS Statistics will be taught in a future chapter For now: –Correlation coefficient –Representative samples are better than biased samples –Less variable cases are better than more variable –Statistical significance: difference is probably not due to chance variation between sample (less than.05)
88 ESSAY WRITING Never use bullets, sentence fragments, etc. Full sentences, essay format required. You do not need to restate the question unless this clarifies your thinking. Underline key terms especially verbs in the question
89 ESSAY WRITING Get to the point, introductions and conclusions are not necessary Address each part of the question Define all terms and give an application or example whenever possible. Underline all terms. Keep your audience in mind.
91 STATISTICS Totally independent: Study Guide; quiet time on your choice of work Need some work on the details: Listen to Mrs. S; work with a partner on Study Guide No background: Listen to Mrs. S; work with Mrs. S Study Guide Tests begin on p. 457
92 Statistical Reasoning Statistical procedures analyze and interpret data allowing us to see what the unaided eye misses. Composition of ethnicity in urban locales
93 Measures of Central Tendency 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 the number of scores that were added together. Median: The middle score in a rank-ordered distribution.
94 Measures of Central Tendency A Skewed Distribution
95 Measures of Variation 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.
97 Making Inferences A statistical statement of how frequently an obtained result occurred by experimental manipulation or by chance.
98 Making Inferences 1.Representative samples are better than biased samples. 2.Less variable observations are more reliable than more variable ones. 3.More cases are better than fewer cases. When is an Observed Difference Reliable?
99 Making Inferences When sample averages are reliable and the difference between them is relatively large, we say the difference has statistical significance. For psychologists this difference is measured through alpha level set at 5 percent. When is a Difference Significant?
100 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.
101 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. Ami Vitale/ Getty Images
102 FAQ Q3. Does behavior vary with gender? Ans: Yes. Biology determines our sex, and culture further bends the genders. However, in many ways woman and man are similarly human.
104 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.
105 FAQ Q6. Is it ethical to experiment on people? Ans: Yes. Experiments that do not involve any kind of physical or psychological harm beyond normal levels encountered in daily life may be carried out.
107 FAQ Q8. Is psychology potentially dangerous? Ans: It can be, but it is not. The purpose of psychology is to help humanity with problems such as war, hunger, prejudice, crime, family dysfunction, etc.