Myers’  PSYCHOLOGY   Chapter 1   Thinking Critically with Psychological Science James A. McCubbin, PhD Clemson University Worth Publishers
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
Limits of Intuition and Common Sense Hindsight Bias   tendency to believe, after learning an outcome, that one would have foreseen it  the “I-knew-it-all-along” phenomenon Overconfidence we tend to think we know more than we do
Limits of Intuition Personal interviewers may rely too much on their “gut feelings” when meeting with job applicants. Taxi/ Getty Images
How Do Psychologists Ask & Answer Questions? Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.
The Scientific Method
A  theory  is   an explanation that integrates principles and organizes and predicts behavior or events. For example, low self-esteem contributes to depression. Theory
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. Hypothesis
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
Research Process
Scientific Methods Descriptive Method –  describes something that is occurring (case studies, surveys, naturalistic observation) Correlational Method gives information on whether there is a relationship between two (or more) things Can NOT establish causation Experimental Method –  manipulates one variable to see if the change effects another variable Can establish causation
Description Methods Case Study A technique in which one person is studied in depth to reveal underlying behavioral principles. Is language uniquely human? Susan Kuklin/ Photo Researchers
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
Survey Wording Effects Can change the results of a survey Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid) False Consensus Effect tendency to overestimate the extent to which others share our beliefs and behaviors
Survey 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. Random Sampling The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.
Naturalistic Observation Observing and recording the behavior of animals in the wild and recording self-seating patterns in a multiracial school lunch room constitute naturalistic observation. Courtesy of Gilda Morelli
Research Strategies Correlation Coefficient a statistical measure of the extent to which two factors vary together and thus how well either factor predicts the other Correlation  coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = +.37
Scatterplots Perfect positive correlation (+1.00) No relationship (0.00) Perfect negative correlation (-1.00)
Data Data showing height and temperament in people.
Scatterplot The Scatterplot below shows the relationship between height and temperament in people.  There is  a moderate positive correlation of +0.63.
Illusory Correlation The perception of a relationship where no relationship actually exists.  Parents conceive children after adoption. Michael Newman Jr./ Photo Edit Confirming evidence Disconfirming evidence Do not adopt Disconfirming evidence Confirming evidence Adopt Do not conceive Conceive
Random Sequences Your chances of being dealt either of these hands is precisely the same:  1 in 2,598,960.
Research Strategies Three Possible Cause-Effect Relationships (1) Low self-esteem Depression (2) Depression Low self-esteem Low self-esteem Depression (3) Distressing events or biological predisposition could cause could cause could cause or or and
Experimental Method Like other sciences, experimentation is the backbone of psychological research.  Experiments isolate causes and their effects. Exploring Cause and Effect
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
Research Strategies Operational Definition a statement of procedures (operations) used to define research variables Example- intelligence may be operationally defined as what an intelligence test measures
Research Strategies Replication repeating the essence of  a research study to see whether the basic finding generalizes to other subjects and circumstances usually with different subjects in different situations
Research Strategies Population all the cases in a group, from which samples may be drawn for a study Random Sample a sample that fairly represents a population because each member has an equal chance of inclusion
Research Strategies Experiment  the investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable) while controlling other relevant factors by random assignment of subjects by random assignment of participants the experiment controls other relevant factors
Research Strategies Double-blind Procedure both the subject and the research staff are ignorant (blind) about whether the subject has received the treatment or a placebo commonly used in drug-evaluation studies 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
Research Strategies Experimental Condition the condition of an experiment that exposes subjects to the treatment, that is, to one version of the independent variable Control Condition the condition of an experiment that contrasts with the experimental treatment  serves as a comparison for evaluating the effect of the treatment
Research Strategies Random Assignment assigning subjects to experimental and control conditions by chance minimizes pre-existing differences between those assigned to the different groups
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
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
Comparison Below is a comparison of different research methods.
Statistical Reasoning Statistical procedures analyze and interpret data allowing us to see what the unaided eye misses. Composition of ethnicity in urban locales
Describing Data A meaningful description of data is important in research. Misrepresentation may lead to incorrect conclusions.
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
Statistical Reasoning A Skewed Distribution 15  20  25  30  35  40  45  50 90 475 710 70 Mode  Median    Mean One Family Income per family in thousands of dollars
Normal Curve A symmetrical, bell-shaped curve that describes the distribution of many types of data (normal distribution). Most scores fall near the mean.
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.
Statistical Reasoning Statistical Significance a statistical statement of how likely it is that an obtained result occurred by chance
Making Inferences When sample averages are reliable and the difference between them is relatively large, we say the difference has statistical significance. It is probably not due to chance variation. For psychologists this difference is measured through alpha level set at 5 percent. When is a Difference Significant?
FAQ Q5.  Is psychology free of value judgments? Ans : No. Psychology emerges from people who subscribe to a set of values and judgments. © Roger Shepard
FAQ Q4.  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. Milgram Experiment Replication

Ch1 thinking critically

  • 1.
    Myers’ PSYCHOLOGY Chapter 1 Thinking Critically with Psychological Science James A. McCubbin, PhD Clemson University Worth Publishers
  • 2.
    Critical Thinking Criticalthinking 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
  • 3.
    Limits of Intuitionand Common Sense Hindsight Bias tendency to believe, after learning an outcome, that one would have foreseen it the “I-knew-it-all-along” phenomenon Overconfidence we tend to think we know more than we do
  • 4.
    Limits of IntuitionPersonal interviewers may rely too much on their “gut feelings” when meeting with job applicants. Taxi/ Getty Images
  • 5.
    How Do PsychologistsAsk & Answer Questions? Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.
  • 6.
  • 7.
    A theory is an explanation that integrates principles and organizes and predicts behavior or events. For example, low self-esteem contributes to depression. Theory
  • 8.
    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. Hypothesis
  • 9.
    Research wouldrequire 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
  • 10.
  • 11.
    Scientific Methods DescriptiveMethod – describes something that is occurring (case studies, surveys, naturalistic observation) Correlational Method gives information on whether there is a relationship between two (or more) things Can NOT establish causation Experimental Method – manipulates one variable to see if the change effects another variable Can establish causation
  • 12.
    Description Methods CaseStudy A technique in which one person is studied in depth to reveal underlying behavioral principles. Is language uniquely human? Susan Kuklin/ Photo Researchers
  • 13.
    Survey A techniquefor ascertaining the self-reported attitudes, opinions or behaviors of people usually done by questioning a representative, random sample of people. http://www.lynnefeatherstone.org
  • 14.
    Survey Wording EffectsCan change the results of a survey Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid) False Consensus Effect tendency to overestimate the extent to which others share our beliefs and behaviors
  • 15.
    Survey If eachmember 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. Random Sampling The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.
  • 16.
    Naturalistic Observation Observingand recording the behavior of animals in the wild and recording self-seating patterns in a multiracial school lunch room constitute naturalistic observation. Courtesy of Gilda Morelli
  • 17.
    Research Strategies CorrelationCoefficient a statistical measure of the extent to which two factors vary together and thus how well either factor predicts the other Correlation coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = +.37
  • 18.
    Scatterplots Perfect positivecorrelation (+1.00) No relationship (0.00) Perfect negative correlation (-1.00)
  • 19.
    Data Data showingheight and temperament in people.
  • 20.
    Scatterplot The Scatterplotbelow shows the relationship between height and temperament in people. There is a moderate positive correlation of +0.63.
  • 21.
    Illusory Correlation Theperception of a relationship where no relationship actually exists. Parents conceive children after adoption. Michael Newman Jr./ Photo Edit Confirming evidence Disconfirming evidence Do not adopt Disconfirming evidence Confirming evidence Adopt Do not conceive Conceive
  • 22.
    Random Sequences Yourchances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
  • 23.
    Research Strategies ThreePossible Cause-Effect Relationships (1) Low self-esteem Depression (2) Depression Low self-esteem Low self-esteem Depression (3) Distressing events or biological predisposition could cause could cause could cause or or and
  • 24.
    Experimental Method Likeother sciences, experimentation is the backbone of psychological research. Experiments isolate causes and their effects. Exploring Cause and Effect
  • 25.
    Many factors influenceour 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
  • 26.
    Research Strategies OperationalDefinition a statement of procedures (operations) used to define research variables Example- intelligence may be operationally defined as what an intelligence test measures
  • 27.
    Research Strategies Replicationrepeating the essence of a research study to see whether the basic finding generalizes to other subjects and circumstances usually with different subjects in different situations
  • 28.
    Research Strategies Populationall the cases in a group, from which samples may be drawn for a study Random Sample a sample that fairly represents a population because each member has an equal chance of inclusion
  • 29.
    Research Strategies Experiment the investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable) while controlling other relevant factors by random assignment of subjects by random assignment of participants the experiment controls other relevant factors
  • 30.
    Research Strategies Double-blindProcedure both the subject and the research staff are ignorant (blind) about whether the subject has received the treatment or a placebo commonly used in drug-evaluation studies 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
  • 31.
    Research Strategies ExperimentalCondition the condition of an experiment that exposes subjects to the treatment, that is, to one version of the independent variable Control Condition the condition of an experiment that contrasts with the experimental treatment serves as a comparison for evaluating the effect of the treatment
  • 32.
    Research Strategies RandomAssignment assigning subjects to experimental and control conditions by chance minimizes pre-existing differences between those assigned to the different groups
  • 33.
    An independentvariable 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
  • 34.
    A dependentvariable 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
  • 35.
    Comparison Below isa comparison of different research methods.
  • 36.
    Statistical Reasoning Statisticalprocedures analyze and interpret data allowing us to see what the unaided eye misses. Composition of ethnicity in urban locales
  • 37.
    Describing Data Ameaningful description of data is important in research. Misrepresentation may lead to incorrect conclusions.
  • 38.
    Statistical Reasoning Modethe 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
  • 39.
    Statistical Reasoning ASkewed Distribution 15 20 25 30 35 40 45 50 90 475 710 70 Mode Median Mean One Family Income per family in thousands of dollars
  • 40.
    Normal Curve Asymmetrical, bell-shaped curve that describes the distribution of many types of data (normal distribution). Most scores fall near the mean.
  • 41.
    Measures of VariationRange: The difference between the highest and lowest scores in a distribution. Standard Deviation: A computed measure of how much scores vary around the mean.
  • 42.
    Statistical Reasoning StatisticalSignificance a statistical statement of how likely it is that an obtained result occurred by chance
  • 43.
    Making Inferences Whensample averages are reliable and the difference between them is relatively large, we say the difference has statistical significance. It is probably not due to chance variation. For psychologists this difference is measured through alpha level set at 5 percent. When is a Difference Significant?
  • 44.
    FAQ Q5. Is psychology free of value judgments? Ans : No. Psychology emerges from people who subscribe to a set of values and judgments. © Roger Shepard
  • 45.
    FAQ Q4. 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. Milgram Experiment Replication

Editor's Notes

  • #6 Preview Question 3: How do theories advance psychological science?
  • #13 Preview Question 4: How do psychologists observe and describe behavior?
  • #22 Preview Question 6: What are illusory correlations?
  • #25 Preview Question 7: How do experiments, powered by random assignment, clarify cause and effect?
  • #38 Preview Question 8: How can we describe data with measures of central tendency and variation?
  • #45 Preview Question 14: Is psychology free of value judgments?
  • #46 Preview Question 13: Is it ethical to experiment on people?