Thinking Critically with Psychological Science Chapter 1
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.
Limits of Human Intuition Exercise
Limits of Intuition
Personal interviewers may rely too much on their “gut feelings” when meeting with job applicants.
Taxi/ Getty Images
Activity
Hindsight Bias
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.
Overconfidence Activity
1)I feel 98 percent certain that the area of the U.S. is more than ____ square miles but less than ____ square miles.
2)I feel 98 percent certain that in 2010 the population of the US was more than ___ but less than ____.
3)I feel 98 percent certain that the number of dogs in America is more than ___ but less than ___.
Overconfidence Activity
4)I feel 98 percent certain that in 2012 the number of female engineers in the United States was more than ___ % of all engineers but less than ___%.
5)I feel 98 percent certain that in 2011 the number of Starbucks in the US was___ but less than ___.
Overconfidence
Sometimes we think we know more than we actually know.
Anagram
BARGE
GRABE
ENTRY
ETYRN
WATER
WREAT
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).
Overconfidence
Anagram
ELEPHANT
LPNTEEAH
CIRCUS
ICSCRU
CHAOS
OCHSA
Now try this word scramble!
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.
Psychological Science
How can we differentiate between uniformed opinions and examined conclusions?
The science of psychology helps make these examined conclusions, which leads to our understanding of how people feel, think, and actas they do!
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).
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
Scientific Method
Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.
Video link: http://www.learner.org/discoveringpsychology/02/e02expand.html
Theory
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.
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 or replicated with different types of populations.
Hypothesis
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
In psychology, a hypothesis is a statement of a relationship between or among variables. (not in text)
Research Observations
So how could we research that People with low self-esteem are apt to feel more depressed?
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.
NB – this is not an experiment.
Research Process
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?
OPERATIONAL DEFINTIONS ACTIVITY
Determine an operational definition for each underlined variable.
Remember an operational definition is observable and measurable.
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.
7. College athletes are not as smart as regular students.
8. Overall senior girls are prettier than sophomore girls.
9. How does grade point average affect a person’s sense of humor?
Anecdotal information can overwhelm general truths
Case Study
Relapse case study HW
Question #1 place symptoms into one of two categories:
Level of functioning
abnormality
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
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
Use interviews or questionnaires to ask about behavior, attitudes, opinions, beliefs, or intentions
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
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?
PROBLEMS WITH QUESTION
1. It is not balanced.
2. It assumes knowledge
3. It does not use everyday language.
4. It employs a perjorative.
It is vague
“Are you in favor of direct retaliatory measures against Franco’s piracy?”
WORDING EFFECTS
Women with young children should be able to work outside the home.
8 in 10 Americans agreed
WORDING EFFECTS
Women should stay at home if they have young preschool children.
7 in 10 Americans agreed
WORDING EFFECTS
Not allowing vs forbidding
More restrictions vs government censorship
Aid to needy vs welfare
Affirmative action vs preferential treatment
WORDING EFFECTS
The problems faced by blacks have been brought on by blacks themselves
With a white interviewer: 62% of whites agreed
With a black interviewer: 46% of whites agreed
What are some problems with a SURVEY?
People may be reluctant to admit undesirable or embarrassing things about themselves.
Or they may say what they think they should say..
Examples?
Survey
A tendency to overestimate the extent to which others share our beliefs and behaviors.
Example?
False Consensus Effect
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.
The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.
Get out of your seats. You may not sit down or lean against anything.
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
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?
Descriptive Methods
Case studies, surveys, and naturalistic observation describe behaviors.
Summary
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
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.
Scatterplots
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
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.
Data
Data showing height and temperament in men.
Scatterplot
The Scatterplot below shows the relationship between height and temperament in men. There is a moderate positive correlation of +0.63.
CORRELATION
POSITIVE CORRELATION: A direct relationship. Two variables increase or decrease together.
NEGATIVE CORRELATION: An inverse relationship. As one variable increases, the other decreases.
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.
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
Guys – if you want keep your hair, don’t get married
Among men, the number of years they are married positively correlates to baldness
So… marriage causes baldness in men, right?
Correlation does not mean causation!!!
or
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
ILLUSORY CORRELATIONS
Examples of Illusory Correlations:
It always rains when …
The phone always rings when…
More serious implications?
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
Correlation
The Point To Remember:
A correlation coefficient helps us see the world more clearly by revealing the extent to which two things relate.
r = +.61
Correlation and Causation
Very important to remember:
Correlation does necessarily prove causation!
Order in Random Events
Given random data, we look for order and meaningful patterns.
Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
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.
Like other sciences, experimentation is the backbone of psychology research. Experiments isolate causes and their effects. Experiments manipulates a factor to determine its effect
Exploring Cause and Effect
Exploring Cause & 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.
Independent Variable
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.
Dependent 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.
IV/DV Activity
Identify the Independent/Dependent Variable.
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
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.
Population
Representative Sample (larger the better)
Experimental Group
Control Group
Apply Methods of Control
Apply Methods of Control
Independent Variable
Placebo
Measure Dependent Variable
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
=
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.
OTHER METHODS OF CONTROL
Eliminating confirmation bias
Eliminating order effects
Matching conditions to eliminate confounding variables
Double blind
Eliminate experimenter bias
Experimentation
A summary of steps during experimentation.
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
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)
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
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.
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.
Comparison
Below is a comparison of different research methods.
Population
Representative Sample (larger the better)
Experimental Group
Control Group
Apply Methods of Control
Apply Methods of Control
Independent Variable
Placebo
Measure Dependent Variable
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
=
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
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)
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
ESSAY WRITING
Get to the point, introductions and conclusions are not necessary
Address each part of the question – sometimes order doesn’t matter
Define all terms and give an application or example whenever possible.
Underline all terms.
Keep your audience in mind.
Practice Outlining Essay
Research Methods
Making Inferences
A statistical statement of how frequently an obtained result occurred by experimental manipulation or by chance.
Making Inferences
Representative samples are better than biased samples.
Less variable observations are more reliable than more variable ones.
More cases are better than fewer cases.
When is an Observed Difference Reliable?
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?
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.
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
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.
FAQ
Q4. Why do psychologists study animals?
Ans: Studying animals gives us the understanding of many behaviors that may have common biology across animals and humans.
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.
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.
FAQ
Q7. Is psychology free of value judgments?
Ans: No. Psychology emerges from people who subscribe to a set of values and judgments.
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.
