Download Chapter 1: Thinking Critically with Psychological

Chapter 1: Thinking Critically with Psychological Science
I.
The Need for Psychological Science
A.
Underestimate perils of intuition
1.
Hindsight bias
a)
Finding that something has happened makes it seem inevitable
b)
Hindsight bias: the tendency to believe after learning an outcome,
that one would have foreseen it. (Also known as the I-knew-it-all-along
phenomenon.)
c)
Errors in recollections and explanations show why we need
psychological research
d)
Just asking people how and why they felt/acted can be misleadingnot because common sense is usually wrong, but b/c it more easily
described what has happened than what will happen
e)
It has been observed in various countries among both children and
adults
f)
Would be surprising if many of psych’s findings had not been
foreseen b/c we all watch behavior
g)
But sometimes intuition is wrong, research has overturned popular
ideas, for ex. familiarity breeds contempt, dreams predict the future, and
emotional reactions coincide with menstrual phase, and surprised us with
discoveries
2.
Overconfidence
a)
Once people know answer, hindsight bias makes it seem obvious
and they become overconfident
b)
Not much better at predicting social behavior: Robert Vallone and
associates (1990) had students predict, on avg. students felt 84% confident
in making self-predictions, later quizzes showed their predictions were
only 71% correct
c)
Even when students were 100% sure of themselves, selfpredictions erred 15% of the time
d)
Ohio State Uni. Psych Philip Tetlock (1998, 2005) collected >
27,000 expert predictions of world events
e)
Repeated findings: predictions, which experts made with 80%
confidence on avg. were right less than 40% of the time
f)
Even those who erred maintained confidence by noting they were
“almost right”
g)
*hindsight bias and overconfidence often lead us to overestimate
intuition, but scientific inquiry can help sift reality from illusion
3.
The Scientific Attitude
a)
1st curiosity-a passion to explore and understand without
misleading or being mislead
b)
Some questions are beyond science; to answer them requires leap
of faith
c)
With other ideas, proof is in pudding; does it work?
d)
Scientific approach long history, even Moses, thru letting facts
speak for themselves: empirical approach
II.
e)
1700s, scientists scoffed at notion that meteorites had
extraterrestrial origins; 2 Yale scientists dared to deviate from
conventional opinion and were right
f)
Today’s truths sometimes become tomorrow’s fallacies
g)
Psychologists approach behavior with curious skepticism, asking 2
questions: What do you mean? How do you know?
h)
When ideas compete, skeptical testing can reveal the ones that best
match the facts
i)
Also need humility: an awareness of our own vulnerability to error
and an openness to surprises and new perspectives
j)
If test subjects don’t behave as ideas predict, then so much the
worse for ideas
k)
3 attitudes: curiosity, skepticism, and humility help make modern
science possible
l)
Founders had religious convictions which made them humble and
skeptical of human authority
m)
Today some religious nuts view science as threat, but scientific
revolution was led mostly by religious people acting on the idea that to
love God, one had to appreciate his work
n)
We are all affected by preconceived ideas, but the ideal unifies
psychologists with all scientists; scientists check and recheck others’
findings and conclusions
4.
Critical Thinking
a)
It examines assumptions, discerns hidden values, evaluates
evidence, and assesses conclusions
b)
Critical thinking: thinking that does not blindly accept arguments
and conclusions
c)
Psychology’s critical inquiry has been open to surprising findings:
(1)
Big loss of brain tissue early may have small long term
effects
(2)
Newborns recognize mom’s odor and voice
(3)
Can learn with brain damage but unaware of learning
(4)
Diverse groups have comparable levels of personal
happiness
(5)
Electroconvulsive shock therapy is good for severe
depression
d)
Also debunked popular presumptions:
(1)
Sleepwalkers not acting out dreams
(2)
Past experience not verbatim
(3)
Most people don’t have weirdly low self-esteem and high
self-esteem not all good
(4)
Opposites don’t attract
e)
Learned=/=believed
How do Psychologists Ask and Answer Questions?
A.
Evaluating theories
1.
The Scientific Method
a)
Theory: an explanation using an integrated set of principles that
organizes observations and predicts behaviors or events
b)
By linking facts and bridging them to deeper principles, theory
offers useful summary
c)
Hypothesis: a testable prediction, often implied by a theory
d)
Letting us test and to reject/revise the theory, predictions give
direction to research and specify what results would support/disconfirm
the theory
e)
Bias subjective observations, ever-present urge to see what we
expect
f)
To check biases, psychologists report research with operational
definitions of procedures and concepts
g)
Operational definition: a statement of the procedures (operations)
use to define research variables; for ex. Human intelligence may be
operationally defined s what an intelligence test measures
h)
Operational definitions allow others to replicate original
observations
i)
Replication: repeating the essence of a research study, usually with
different participants in different situations, to see whether basic finding
extends to other participants and circumstances
j)
If other researches recreate and get similar results, confidence in
finding’s reliability grows
k)
The scientific method: self-correcting process for asking questions
and observing nature’s answers
l)
Good theories explain by:
(1)
Organizing and linking observed facts
(2)
Implying hypotheses that offer testable predictions and,
sometimes, practical applications
m)
Research leads to revised theory that better organizes and predicts
n)
Test hypotheses and refine theories using descriptive (which
describe behaviors, often using case studies, surveys, or naturalistic
observations), correlational (which associate different factors), and
experimental (which manipulate factors to discover their effects) methods
2.
Description: psychologists observe and describe people more objectively
and systematically
a)
The Case Study
(1)
Case study: an observation technique in which 1 person is
studies in depth in the hope of revealing universal principles; for
ex.: particular impairment after damage to certain brain region,
children’s thinking, chimp capacity for understanding and
language
(2)
Case studies often suggest directions for further study and
show what can happen, but can mislead if person studied is
atypical
(3)
*individual cases can suggest fruitful ideas; what’s true for
all of us can be glimpsed in any one of us, but to discern the
general truths that cover individual cases, we must use other
research methods
b)
The Survey
(1)
Survey method looks at many cases in less depth
(2)
Survey: a technique for ascertaining the self-reported
attitudes or behaviors of a particular group, usually by questioning
a representative, random sample of the group
(a)
Wording effects
(i)
Subtle changes in order of wording can have
major effects
(ii)
Critical thinkers reflect on how the phrasing
of a question might affect people’s expressed
opinions
(b)
Random Sampling
(i)
Accurate picture of whole population’s
attitudes and experiences-representative sample
(ii)
*the best basis for generalizing is from a
representative sample of cases
(iii)
Population: all the cases in a group being
studied, from which samples may be drawn. (Note:
except for national studies, this doesn’t refer to a
country’s whole population.)
(iv)
Random sample: a sample that fairly
represents a population because each member has
an equal chance of inclusion
(v)
*before accepting survey findings, think
critically: consider the sample; can’t compensate for
unrepresentative sample by adding more people
c)
Naturalistic Observation
(1)
Naturalistic observation: observing and recording behavior
in naturally occurring situations without trying to manipulate and
control the situation
(2)
Doesn’t explain, only describes
(3)
Still reveals, ex. We thought only humans use tools, but
chimps do too; paved way for later studies of animal behavior and
further expanded out understanding
d)
Whiten and Byrne (1988) saw baboon pretend to be attacked so
mom drive others away from its good
e)
More developed a primate species’ brain, more likely display
deceptive behaviors (Byrne & Corp. 2004)
f)
Human behavior
(1)
Laugh 30x more often in social than alone, 17 muscles
contort mouth and squeeze eyes, emit a series of 75-millisecond
vowel-like sounds that are spaced about 1/5th of second apart
(Provine 2001)
3.
4.
(2)
Mehl and Pennebaker (2003) equipped 52 students from
University of Texas with tape recorders; up to 4 days, recorder
captured 30 seconds of students’ waking hours every 12.5 minutes,
>10,000 half-minute slices (28% talking with someone, 9%
computer keyboard)
(3)
Levine and Norenzayan (1999) compare pace of life in 31
countries (operational definition pace of life included walking
speed, speed postal clerks completed simple request and accuracy
of public clocks) life fastest paced in Japan and Western Europe
and slower paced in economically less-developed countries; colder
climates live at faster pace (and more prone to die from heart
disease)
g)
Doesn’t control for all the factors that may influence behavior
h)
Provide data for correlational research
Correlation
a)
Describing behaviors is 1st step toward predicting it, survey and
naturalistic observation show us if one trait/behavior related to another
b)
Correlation: a measure of the extent to which 2 factors vary
together, and thus of how well either factor predicts the other
c)
Statistical measures help figure how closely 2 things vary together
and how well either 1 predicts the other
d)
Correlation coefficient: a statistical index of the relationship
between 2 things (from -1 to +1).
e)
Scatterplots: a graphed cluster of dots, each of which represents the
values of 2 variables, the slope of the points suggests the direction of the
relationship between the two variables, the amount of scatter suggests the
strength of the correlation (little scatter indicates high correlation)
f)
Perfect correlations rarely occur
g)
Each dot represents scattered values of 2 variables
h)
Correlation (+) if 2 sets of scores tend to rise and fall together,
saying correlation is “neg” says nothing of strength or weakness
i)
(+1.00) perfect positive, no relationship (0.00), (-1.00) perfect
negative
j)
Correlation is neg if 2 sets relate inversely
k)
Stats help see what naked eye misses, case by case, see no
correlation
l)
*correlation coefficient helps us see the world more clearly by
revealing the extent to which 2 things relate
*Correlation and Causation
a)
Correlations help predict
b)
No matter how strong the correlation, doesn’t prove cause-andeffect; 3rd factor could explain correlation
c)
Association (not just correlation but also other associations verified
by other non-experimental statistics) does not prove causation
d)
*correlation indicates possibility of cause-effect relationship but
does not prove causation
5.
B.
Illusory Correlations
a)
The perception of a relationship where none exists
b)
When we believe there is a relationship, we are more likely to
notice and recall instances that confirm our belief
c)
*when we notice random coincidences, we may forget they are
random and see them as correlated and deceive ourselves by seeing what
is not there
6.
Perceiving Order in Random Events
a)
Random sequences often don’t look random
b)
Kahneman and Tversky (1972) found that most people believe
HTTHTH most likely when all equally likely
c)
Event with 1 out of a billion chance happens about 6 times a day
Experimentation
1.
Experiment: a research method in which an investigator manipulates 1 or
more factors (independent variables) to observe the effect on some behavior or
mental process (the dependent variable); by random assignment of participants,
the experimenter aims to control other relevant factors
2.
Correlational research can’t control for all possible factors
3.
Experiments enable that focus on the possible effects of 1 or more factors
by:
a)
Manipulating the factors of interest
b)
Holding constant (“controlling”) other factors
4.
Random Assignment
a)
No single experiment is conclusive
b)
Random assignment: assigning participants to experimental and
control groups by chance, thus minimizing pre-existing differences
between those assigned to the different groups
c)
Eliminates alternative explanations by holding constant all other
factors
d)
If behavior changes when we vary experimental factor, then factor
is having an effect
e)
*unlike correlational studies, which uncover naturally occurring
relationships, an experiment manipulates a factor to determine its effect
f)
1 group receives treatment and other a placebo
g)
Double-blind procedure: an experimental procedure in which both
the research participants and research staff are ignorant (blind) about
whether the research participants have received the treatment or a placebo,
commonly used in drug-evaluation studies
h)
Researches can check treatment’s actual effects apart from the
participants’ belief in its healing powers and the staff’s enthusiasm for its
potential
i)
Placebo (Latin “I shall please”) effect: experimental results caused
by expectations alone; any effect on behavior caused by the administration
of an inert substance or condition, which the recipient assumes is an active
agent
j)
More expensive the placebo, the better if works
III.
k)
Must control for placebo effect
l)
Double blind one way to create experimental and control group
m)
Experimental group: in an experiment, the group that is exposed to
the treatment, that is, to one version of the independent variable
n)
Control group: the group that is not exposed to the treatment;
contrasts with the experimental group and serves as a comparison for
evaluating the effect of the treatment
o)
By randomly assigning people to these conditions, fairly certain
the 2 groups are otherwise identical; random assignment roughly equalizes
the 2 groups in age, attitudes, and every other characteristic
p)
With random assignment, conclude any later different between
experimental and control groups will be result of treatment
5.
Independent and Dependent Variables
a)
Independent variable: the experimental factor that is manipulated;
the variable whose effect is being studied
b)
Vary independently of other factors which random assignment
control
c)
Dependent variable: the outcome factor; the variable that may
change in response to manipulations of the independent variable, usually
behavior/mental process
d)
Both variables given operational definition which specify
procedures that manipulate the individual variable or measure the
dependent variable
e)
Distinction between random sampling (helps us generalize to a
larger population) and random assignment (controls extraneous influences,
which help infer cause and effect)
f)
Recap. variable-anything that can vary, experiments aim to
manipulate an independent variable, measure the dependent variable, and
control all other variables; an experiment has at least 2 groups: an
experimental and comparison/control, random assignment works to equate
groups before any treatment effects
g)
Experiments test effect of at least 1 independent variable (what we
manipulate) on at least 1 dependent variable (the outcome we measure)
Statistical Reasoning in Everyday Life
A.
*Doubt big, round, undocumented #s, rather than swallowing top-of-the-head
estimates, focus on thinking smarter by applying simple statistical principles to everyday
reasoning
B.
Describing Data
1.
Bar graph: make difference look big/small by how one labels vertical
scale/Y-axis
2.
*when viewing figures in magazines and on TV, read scale labels and note
their range
3.
Measures of Central Tendency
a)
Next step-summarize the date using some measure of central
tendency, a single score that represents a whole set of scores; problems if
distribution skewed and paints inaccurate picture
C.
b)
Simplest measure-mode: the most frequently occurring score or
scores in a distribution
c)
Most commonly reported-mean: the arithmetic average of a
distribution, obtained by adding the scores and then dividing by the # of
scores
d)
Median: midpoint, 50th percentile, the middle score in a
distribution; half the scores are above it and half are below it
e)
Ex. Income data, mean, median, and mode, very different because
mean biased by few extreme scores; if Bill Gates moved to your
neighborhood, mean goes up but median still same
f)
*Always note which measure of central tendency is reported, then,
if it is a mean, consider whether a few atypical scores could be distorting it
4.
Measures of Variation
a)
Helps to know something about the amount of variation in the
data-how similar or diverse scores are
b)
Argument derived from scores with low variability are more
reliable than argument based on scores with high variability
c)
Range-the difference between the highest and lowest scores in a
distribution, provides only crude estimate of variation because a couple of
extreme scores in otherwise uniform group will create deceptively large
range
d)
More useful standard for measuring how much scores deviate from
another is the standard deviation-a computed measure of how much scores
vary around the mean score, better gauges whether scores are packed or
dispersed because it uses info from each score, computes or assembles
info about how much individual scores differ from mean
e)
Standard deviation=sqrt[sum of (deviations)^2/# of scores]
f)
Normal curve: (normal distribution) a symmetrical, bell-shaped
curve that describes the distribution of many types of data (such as the
Wechsler intelligence scores); most scores fall near the mean (68% fall
within 1 standard deviation of it) and fewer and fewer near the extremes
g)
95% fall within 2 standards deviations
Making Inferences
1.
Average score in 1 group could differ from average score in another not
because of any real difference but because of chance fluctuations in the people
sampled
2.
How confidently can we inter that an observed difference accurately
estimates the true difference? We can ask how reliable and significant the
difference is
3.
When is an Observed Difference Reliable?
a)
Representative samples better than biased samples: best basis for
generalizing is from a representative sample of cases, keep in mind what
population a study has sampled
b)
Less-variable observations are more reliable than those that are
more variable: an average is more reliable when it comes from scores with
low variability
IV.
c)
More cases are better than fewer: averages based on many cases
are more reliable (less variable) than averages based on only a few
d)
*Don’t be overly impressed by a few anecdotes, generalizations
based on a few unrepresentative cases are unreliable
4.
When is a Difference Significant?
a)
When 2 samples are each reliable measures of their respective
populations (as when each is based on many observations that have small
variability), then their difference is likely to be reliable as well
b)
When difference is large, even more confidence that the difference
reflects real difference in their population
c)
When sample averages are reliable and when difference between
them is relatively large, has statistical significance-a statistical statement
of how likely it is that an obtained result occurred by chance, high
significance means that observed difference is probably not due to chance
variation between the samples
d)
Not much of finding unless the odds of it occurring by chance <5%
(arbitrary criterion)
e)
May be stat sig but have little practical sig, ex. 1st borns and later
borns high sig tendencies for 1st borns to have higher average scores than
siblings but scores differ by so little no practical importance
f)
Some advocate alternative to significance testing, use other way to
express effect size-its magnitude and reliability
g)
*stat sig indicates the likelihood that a result will happen by
chance, but doesn’t say anything about importance
Frequently Asked Questions About Psychology
A.
Can lab experiments illuminate everyday life?
1.
Lab environments intended to be simplified reality; experiment’s purpose
isn’t to recreate exact behaviors but to test theoretical principles-resulting
principles-not specific findings that help explain everyday behaviors, principles
refined every experiment, many investigations show that principles from lab do
generalize to everyday world
2.
*psych’s concern is less with particular behaviors than with general
principles that help explain many behaviors
B.
Does behavior depend on one’s culture and gender?
1.
Culture-the enduring behaviors, ideas, attitudes, and traditions shared by a
group of people and transmitted from 1 generation to the next-matters
2.
Culture shapes behavior-being aware of such differences can restrain
assumptions that others will think/act as we do
3.
Shared biological heritage unites us-same underlying processes guide
people everywhere:
a)
People with dyslexia exhibit same brain malfunction whether
Italian/French/British
b)
Variation in language may impede communication across cultures
yet all language share principles of grammar and people from opposite
hemispheres can communicate with smile/frown
C.
D.
c)
People in different cultures vary in feelings of loneliness, but
across cultures, loneliness is magnified by shyness, low self-esteem, and
being unmarried
4.
Studying people of all races/cultures helps us discern similarities and
differences, human kinship and diversity
5.
Gender matters: differences in what we dream, how we express and detect
emotions, and in risk for alcohol dependence, depression, and eating disorders
6.
Psychologically similar
7.
*even when specific attitudes and behaviors vary by gender/across culture,
underlying processes much the same
Why do psychologists study animals, and is it ethical to experiment on animals?
1.
Want to understand how different species learn, think, and behave; study
animals to learn about people
2.
Humans experiments led to treatments, human processes seen in other
mammals
3.
Animals simpler, more revealing
4.
Animal protection movement protests the use of animals in
psychological/medical research
5.
Psychology responds with examples of animal testing leading to vaccines
6.
US & Canada 60%; Britain 37% okay
7.
Two issues:
a)
Whether right to place well-being of humans above that of animals
(1)
Compassion for animals vary, as does compassion for
people-based on perceived similarity to us
(2)
Value animals according to their perceived kinship with us
(ranks):
(a)
Primates/companion pets get top priority
(b)
Other mammals
(c)
Birds, fish, and reptiles
(d)
Insects
(e)
Draw own cut-offline
b)
Priority given to well-being of animals in research: what
safeguards?
(1)
Professional associations and funding agencies already
have guidelines
(a)
BPS: housing under reasonably natural living
conditions with companions for social animals
(b)
APA: ensure “comfort, health, and humane
treatment” and minimize “infection, illness, and pain”
8.
Animals benefitted from animal research to improve care/management in
animals’ natural habitat
9.
Reveal behavioral kinship with animals, experiments have led to increased
empathy/protection
Is it ethical to experiment on people?
1.
Temporary stress/deception but when necessary to justifiable end
E.
2.
Ethical principles developed by APA (1992), by BPS (1993) and
psychologists international urge investigators to
a)
Obtain the informed consent of potential participants
b)
Protect them from harm and discomfort
c)
Treat informational about individual participants confidentially
d)
Fully explain research afterwards
3.
Most universities today screen research proposals through ethics
committee that safeguards well-being of every participant
4.
Researcher-informative and considerate, participant learn something and
most enjoy engagement
5.
Stores research without ethics committee
Is psychology free of value judgments? No.
1.
Values affect what we study, how we study, and how we interpret results
2.
Preconceptions bias observations/interpretation
3.
Words have different connotations and reflect values
4.
Accept value-laden advice when ask for professional guidance
5.
Psychology can deceive but intent is to enlighten
6.
Psychology helps problems and speaks to our desire of
nourishment/love/happiness
7.
Kenneth/Mamie Phipps Clark (1947): when given choice between
black/white dolls most African-Americans chose white doll, internalized antiblack prejudice
perspective
neuroscience
evolutionary
behavior genetics
psychodynamic
behavioral
cognitive
social-cultural
Research
Method
Descriptive
Correlational
Experimental
focus
how the body and brain enable emotions, memories, and sensory
experiences
how the natural selection of traits promoted the survival of genes
how much our genes and environment influence our individual differences
how behavior springs from unconscious drives and conflicts
how we learn observable responses
how we encode, process, store, and retrieve info
how behavior and thinking vary across situations and cultures
Comparing Research Methods
Basic Purpose
How Conducted
What is
Manipulated
To observe and
Do case studies,
n/a
record behavior
surveys, or
naturalistic
observations
To detect naturally
Compute statistical n/a
occurring
association,
relationships; to
sometimes among
assess how well one survey responses
variable predicts
another
To explore cause
Manipulate 1 or
Independent
and effect
more factors; use
variable
random assignment
Weaknesses
No control of
variables;
single cases
may be leading
Doesn’t specify
cause and effect
Sometimes not
feasible; results
may not
generalize to
other contexts,
not ethical to
manipulate
certain
variables