Myers’ PSYCHOLOGY

(6th Ed)

Chapter 1 Thinking Critically with Psychological Science

James A. McCubbin, PhDClemson UniversityWorth Publishers

“What good fortune for those in power that people do not think.”

Thinking Critically with Psychological Science

Critical Thinking Thinking that does not blindly

accept arguments and conclusions examines assumptions discerns hidden values evaluates evidence

Limits of Intuition and Common Sense

Hindsight Bias (20/20 hindsight vision)

tendency to believe, after learning an outcome, that one would have foreseen it

the “I-knew-it-all-along” phenomenonOverconfidence

we tend to think we know more than we do (more confident than correct)

History is Living Proof

“We don’t like their sound. Groups of guitars are on there way out.” Decca Records, 1962, Beatles Recording Contract

“Computers in the future may weigh no more than 1.5 tons.” Popular Mechanics, 1949

“The telephone may be appropriate for our American cousins, but not here, because we have an adequate supply of message boys.” British expert group evaluating the telephone

The Scientific Attitude

Curiosity– a passion to explore and understand without misleading or being mislead

Skeptical, but not cynical (open, but not gullibleWilling to question any truth claim, asking for

clarity in definition, consistency in logic, adequacy of evidence “Paul Kurtz”

Humility– ability to reject one’s own ideas

Smart Thinking=Critical Thinking

Research Strategies

Theory an explanation using an integrated

set of principles that organizes and predicts observations

Hypothesis a testable predictionoften implied by a theory

The Scientific Method

generate or refine

research and observations

lead to

hypothesis

theories

Research Strategies

Operational Definitiona statement of procedures

(operations) used to define research variables

Example- intelligence may be operationally defined

as what an intelligence test measures

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

Case Studyan observation technique in which one

person is studied in depth in the hope of revealing universal principles

Research Strategies

Surveytechnique for ascertaining the self-

reported attitudes or behaviors of peopleusually by questioning a representative,

random sample of themFalse Consensus Effect

tendency to overestimate the extent to which others share our beliefs and behaviors

Research Strategies

Populationall the cases in a group, from which

samples may be drawn for a studyRandom Sample

a sample that fairly represents a population because each member has an equal chance of inclusion

Research Strategies

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

Research Strategies

Naturalistic Observationobserving and recording behavior in

naturally occurring situations without trying to manipulate and control the situation

Research StrategiesCorrelation 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 directionof relationship

(positive or negative)

Indicates strengthof relationship(0.00 to 1.00)

r = +.37

Research Strategies

Scatterplota graphed cluster of dots, each of which

represents the values of two variablesthe slope of the points suggests the

direction of the relationshipthe amount of scatter suggests the

strength of the correlation little scatter indicates high correlation

also called a scattergram or scatter diagram

Research Strategies

Perfect positivecorrelation (+1.00)

No relationship (0.00) Perfect negativecorrelation (-1.00)

Research Strategies

Scatterplot of Height and Temperament

55 60 65 70 75 80 85

959085807570656055504540353025

Temperamentscores

Height in inches

Research StrategiesHeight and Temperament of 20 Men

123456789

10

11121314151617181920

80636179746962757760

64767166737063716870

75666090604242608139

48697257637530578439

SubjectHeight in

Inches Temperament SubjectHeight in

Inches Temperament

Research StrategiesThree Possible Cause-Effect Relationships

(1)Low self-esteem

Depression

(2)Depression

Low self-esteem

Low self-esteem

Depression

(3)Distressing events

or biologicalpredisposition

could cause

could cause

could cause

or

or

and

Illusory Correlation

Illusory Correlationthe

perception of a relationship where none exists

Conceive Do not conceive

Adopt

Do notadopt

disconfirming evidence

confirming evidence

disconfirming evidence

confirming evidence

Random Sequences

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

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 Procedureboth 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 studiesPlacebo

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 Conditionthe condition of an experiment that

exposes subjects to the treatment, that is, to one version of the independent variable

Control Conditionthe condition of an experiment that

contrasts with the experimental treatment serves as a comparison for evaluating the

effect of the treatment

Research Strategies

Random Assignmentassigning subjects to experimental and control conditions by chance

minimizes pre-existing differences between those assigned to the different groups

Research Strategies

Independent Variable the experimental factor that is manipulatedthe 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

Research Strategies

Comparing Research MethodsResearch Method Basic Purpose How Conducted What is

Manipulated

Descriptive To observe and Case studies, surveys, Nothing record behavior and naturalistic

observations

Correlational To detect naturally Computing statistical Nothing occuring relationships; association, sometimes to assess how well among survey one variable predicts responses

Experimental To explore cause Manipulating one or Independent and effect more factors and using variable(s)

random assignmentto eliminate preexistingdifferences among subjects

Research Strategies

Design of the subliminal tapes experiment

Subliminal tape content

Self-esteem Memory

Memory

Self-esteem

Tape label

Statistical Reasoning

Our Brand Brand BrandBrand X Y Z

100%

99

98

97

96

95

Percentagestill functioningafter 10 years

Brand of truck

Statistical Reasoning

Our Brand Brand Brand Brand X Y Z

100%

90

80

70

60

50

40

30

20

10

0

Percentagestill functioningafter 10 years

Brand of truck

Statistical ReasoningMode

the most frequently occurring score in a distribution

Meanthe arithmetic average of a distributionobtained by adding the scores and then dividing

by the number of scoresMedian

the middle score in a distributionhalf the scores are above it and half are below it

Statistical ReasoningA 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

Statistical ReasoningRange

the difference between the highest and lowest scores in a distribution

Standard Deviationa computed measure of how much scores

vary around the meanStatistical Significance

a statistical statement of how likely it is that an obtained result occurred by chance

Does Behavior Depend on One’s Culture?

Culturethe enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next