Transcript Chapter 1:

Chapter 1:
Thinking Critically With
Psychological Science
1
SQ3R
 Survey, Question, Read, Recite, and
Review, SQ3R is a study method that
encourages active processing of new
information.
 Distributing study time, listening actively
in class, overlearning, focusing on big
ideas, and being a smart test-taker will
also boost learning and performance.
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Intro
 Our intuition is often wrong when it
comes to physical reality
 If you drop a bullet off a table 3 feet
high, and fire another one straight
across an empty football field, which
hits the ground first?
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Intro
 We are all amateur psychologists, suggested
Fritz Heider, who attempted to explain others’
behavior (see Chapter 18). That need for a
coherent world, however, sometimes leads to
error.
 There are limits to intuition and common
sense
 It is surprising that just a few minutes after
seeing the effect scene, people would
reliably claim to have seen the cause scene.
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Intro
 We tend to believe that we can
accurately remember what we saw just
a few minutes ago.
 Memory for pictures tends to be more
accurate than memory for words.
 We put a lot of confidence in things that
we have seen with our own eyes.
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Intro
 Application to eyewitness testimony in
the courtroom is clear. Typically, cases
go to trial many months after the events
occur, very likely making eyewitnesses
more vulnerable to inference-based
errors. Misremembering the causes of
others’ behavior over long periods may
also foster conflict in social
relationships.
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Intro
 Importantly, the research indicated that
causal-inference errors were common in a
backward but not a forward direction.
 That is, exposure to “effect” pictures caused
illusory memories of seeing “cause” pictures,
but exposure to “cause” pictures did not
produce false memories of seeing “effect”
pictures. The researchers speculate that
there is a stronger need to answer “Why?”
than to answer “What would happen if . . .
?”
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Hindsight Bias
 I-knew-it-all-along phenomenon
 Is the tendency to believe, after learning an
outcome, that one would have foreseen it.
 Finding out that something has happened
makes it seem inevitable.
 Thus, after learning the results of a study in
psychology, it may seem to be obvious
common sense.
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However………..
 Experiments have found that events
seem far less obvious and predictable
beforehand than in hindsight.
 Sometimes psychological findings even
jolt our common sense.
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Overconfidence
 The Confirmation Bias: Overconfidence stems
partly from our tendency to search for
information that confirms our preconceptions.
 Our everyday thinking is limited by our
tendency to think we know more than we do.
 Asked how sure we are of our answers to
factual questions, we tend to be more
confident than correct.
 Despite lackluster predictions, the
overconfidence of experts is hard to dislodge.10
Overconfidence
 It is really
intellectual conceit!!!
 The Psychic: ESP……….
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Scientific attitude encourages
critical thinking
 Scientific attitude reflects a hard-
headed curiosity to explore and
understand the world without being
fooled by it.
 Critical thinking: examine
assumptions, discern hidden values,
evaluate evidence, and assess
conclusions.
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Scientific attitude encourages
critical thinking
 Active listening and participation is a
requirement for learning and mastering a
subject.
 The study of psychology can help us to think
critically. Remember that psychologists are
scientists.
 The scientific approach can help us evaluate
competing claims and ideas regarding
phenomena ranging from subliminal
persuasion, ESP, and mother-infant bonding
to astrology, basketball streak-shooting, and
hypnotic age regression.
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Scientific attitude encourages
critical thinking
 An important goal of this course is to
teach questioning thinking that
examines assumptions, discerns hidden
values, evaluates evidence, and
assesses conclusions.
 Psychology’s critical inquiry has
produced surprising findings that have
sometimes debunked popular beliefs.
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Scientific attitude encourages
critical thinking
 While making decisions, discerning
people will welcome the powers of
their gut wisdom yet know when to
restrain it with rational, reality-based
critical thinking. (e.g., assessing
suicide risk, jurors, truth from
deception, sports, religion).
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Scientific attitude encourages
critical thinking
 Our intuitions provide us with useful
insights but they can also seriously
mislead us.
 The scientific method provides us with
a very important tool in helping us sift
sense from nonsense.
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Scientific attitude encourages
critical thinking
 Randolph A. Smith’s Challenging Your
Preconceptions: Thinking Critically
About Psychology:
 Guidelines for critical thinking…
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Scientific attitude encourages
critical thinking

Smith’s Guidelines for critical
thinking…
Critical thinkers are open-minded.
They can live with uncertainty and
ambiguity.
2. Critical thinkers are able to identify
inherent biases and assumptions.
They know that people’s beliefs and
experiences shape the way they view
and interpret their worlds.
1.
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Scientific attitude encourages
critical thinking

Smith’s Guidelines for critical thinking…
3.
Critical thinkers practice an attitude of
skepticism. They have trained themselves to
question the statements and claims of even
those people they respect. They are ready to
reexamine their own ideas.
4.
Critical thinkers distinguish facts from
opinions. They recognize the need to rely on
scientific evidence rather than personal
experience.
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Scientific attitude encourages
critical thinking

Smith’s Guidelines for critical thinking…
5. Critical thinkers don’t oversimplify. They
realize the world is complex and there may be
multiple causes for behavior.
6.
Critical thinkers use the processes of logical
inference. They carefully examine the
information given and recognize
inconsistencies in statements and conclusions.
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Scientific attitude encourages
critical thinking

Smith’s Guidelines for critical
thinking…
7. Critical thinkers review all the
available evidence before
reaching a conclusion. They will
consult diverse sources of
information and consider a variety
of positions before making a
judgment.
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Psychological theories guide
scientific research
 A useful theory effectively organizes a
wide range of observations and implies
testable predictions, called
hypotheses.
 Research: test and reject or revise a
particular theory.
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The Science of Psychology:
The Scientific Method
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Predictions
 They specify in advance what results
would support the theory and what
results would disconfirm it.
 As an additional check on their own
biases, psychologists report their results
precisely with clear operational
definitions of concepts.
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Operational Definitions
 Define research variables that allow
others to replicate, or repeat, their
observations.
 Often, research leads to a revised
theory that better organizes and
predicts observable behaviors or
events.
 Must be clear, concise, specific!
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Case Studies
 Case Studies are a method by which
psychologists analyze one or more
individuals or groups in great depth in
the hope of revealing things true of us
all. While individual cases can suggest
fruitful ideas, any given individual may
be atypical, making the case
misleading.
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Case Studies
 Leary identifies four uses of the case
study in behavioral research.
 First, as the text suggests, a case
study may be used as a source of
insights and ideas, particularly in the
early stages of investigating a specific
topic. (e.g., Freud’s theory of psychoanalysis
emerged from his case studies of therapy clients.
Piaget’s theory of cognitive development arose from
case studies of his own children)
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Case Studies
 Second, case studies may be used to
describe particularly rare phenomena
(e.g., people who have killed or tried to kill U.S.
presidents; Investigations of mass murders also are
limited to a case study approach; Luria used a case
study to describe another rare phenomenon—a man
who had nearly perfect memory).
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Case Studies
 Third, case studies in the form of
psychobiographies involve the
application of psychological
concepts and theories in an effort
to understand the lives of famous
people, such as da Vinci, Martin
Luther, Mahatma Gandhi, Richard
Nixon.
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Case Studies
 Finally, case studies provide
illustrative anecdotes. Researchers
and teachers often use case
studies to illustrate general
principles to other researchers and
to students.
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Case Studies
 There are at least two important limitations
of case studies.
 First, they are virtually useless in providing
evidence to test behavioral theories or
treatments. The lives and events studied
occur in uncontrolled fashion and without
comparison information. No matter how
reasonable the investigator’s explanations,
alternative explanations cannot be ruled out.
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Case Studies
 Second, most case studies rely on the
observations of a single investigator.
Thus, we often have no way of assessing the
reliability or validity of the researcher’s
observations or interpretations.
 Because the researcher may have a vested
interest in the outcome of the study (e.g.,
whether a therapy works), one must always
be concerned about self-fulfilling
prophecies and demand characteristics.
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Surveys
 The survey looks at many cases in less depth
and asks people to report their behavior or
opinions. Asking questions is tricky because
even subtle changes in the order or wording
of questions can dramatically affect
responses.
 A limitation: what people say and what they
do are often two very different things.
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Bias
 We are vulnerable to the false
consensus effect, whereby we
overestimate others’ agreement with us.
 The survey ascertains the self-reported
attitudes or behaviors of a population by
questioning a representative, random
sample.
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Representative Sample
 Obtaining a representative sample of even a
well-defined population may not be easy.
 Who
has a phone
 Who will actually vote
 Who is on what list
 Time of day call is made
 How many surveys sent vs. how many returned
 Compared to what!!!!!!!!! (e.g., recommended
by more than 75% of dentists)
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Naturalistic Observation
 Consists of observing and recording the
behavior of organisms in their natural
environment.
 Like the case study and survey
methods, this research strategy
describes behavior but does not
explain it.
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Correlations
 When surveys and naturalistic observations
reveal that one trait or behavior accompanies
another, we say the two correlate.
 A correlation coefficient is a statistical
measure of relationship.


a positive correlation indicates a direct relationship,
meaning that two things increase together or decrease
together.
a negative correlation indicates an inverse relationship:
As one thing increases, the other decreases.
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Correlations
 The tendency to interpret correlations in
terms of cause and effect is a common
error.
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Correlations
 Hippocrates’ delightful Good News Survey (GNS) was
designed to illustrate errors that can be hidden in
seemingly sound scientific studies.
 The survey found that people who often ate Frosted
Flakes as children had half the cancer rate of those
who never ate the cereal.
 Conversely, those who often ate oatmeal as children
were four times more likely to develop cancer than
those who did not.
 Does this mean that Frosted Flakes prevents cancer
while oatmeal causes it?
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Correlations
 What are the explanations for these
correlations. The answer?
 Cancer tends to be a disease of later life.
Those who ate Frosted Flakes are younger. In
fact, the cereal was not around when older
respondents were children, and so they are
much more likely to have eaten oatmeal.
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Correlations
 Scientists have linked television-watching with
childhood obesity. In fact, the degree of
obesity rises 2 percent for each hour of
television viewed per week by those aged 12
to 17, according to a study in the Journal of
the American Academy of Pediatrics.
 One explanation is that TV watching results
in less exercise and more snacking (often
on the high-calorie, low-nutrition foods pitched
in commercials). Is that conclusion justified?
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Correlations
 What are some alternative explanations for
the correlation?
 The causal relationship may be reversed.
Obesity may lead children to prefer more
sedentary activities, such as TV viewing.
 Or, some third factor may explain the
relationship. For example, parents having little
formal education may not emphasize good
nutrition or good use of leisure time.
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Correlations
Misinterpreting Correlations:
 Keith Stanovich has identified two major
classes of ambiguity in correlational research:
the “directionality problem” and the “third
variable possibility.”
 Directionality Problem: Researchers have long
known about the correlation between eyemovement patterns and reading ability: Poorer
readers have more erratic patterns (moving
the eyes from right to left and making more
stops) per line of text.
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Correlations
directionality problem:
 In the past, however, some educators
concluded that “deficient oculomotor skills”
caused reading problems and so developed
“eye-movement training” programs as a
corrective. Many school districts may still have
“eye-movement trainers,” representing
thousands of dollars of equipment, gathering
dust in their storage basements.
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Correlations
directionality problem:
 Careful research has indicated that the eye
movement/reading ability correlation reflects a causal
relationship that runs in the opposite direction.
 Slow word recognition and comprehension difficulty
lead to erratic eye movements.
 When children are taught to recognize words
efficiently and to comprehend better, their eye
movements become smoother.
 Training children’s eye movements does nothing to
enhance their reading comprehension.
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Correlations
Third variable possibility:
 Basically, a third variable account for the
problem. E.g., an unexpected virus.
 Poor people living in an area with poor
sanitation contract a serious disease. After
more research, however, the cause was found
to be related to an inadequate diet- nothing at
all to do with the sanitary conditions.
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Correlation Vs. Casuation
 Perhaps the most irresistible thinking error is
to assume that correlation proves causation.
 Correlation reveals how closely two things
vary together and thus how well one predicts
the other.
 However, the fact that events are correlated
does not mean that one causes the other.
 Thus, while correlation enables prediction, it
does not provide explanation.
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Correlations
Exercise
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Scatter Plots
 Researchers depict scores on graphs
called scatterplots; each point plots the
value of two variables.
 The correlation coefficient helps us to
see the world more clearly by revealing
the extent to which two things relate.
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Illusory Correlation
 The perception of a relationship where none
exists, often occurs because our belief that a
relationship exists leads us to notice and
recall confirming instances of that belief.
 Because we are sensitive to unusual events,
we are especially likely to notice and
remember the occurrence of two such events
in sequence, for example, a premonition of an
unlikely phone call followed by the call.
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 Given even random data, we look for
meaningful patterns. We usually find
order because random sequences often
don’t look random.
 Apparent patterns and streaks (such as
repeating digits) occur more often than
people expect.
 Failing to see random occurrences for
what they are can lead us to seek
extraordinary explanations for ordinary
events.
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 Failure to take into account all the relevant
information also helps explain certain
common misconceptions:
 (1) because more accidents occur at home
than elsewhere, we may believe it’s more
dangerous to be at home, and
 (2) because more violence is committed
against members of one’s own family than
against anyone else, we may conclude it is
more dangerous to be around family
members than around strangers.
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 The problem is that we spend more time at
home than any other place and we are also
around our relatives more than anyone else.
 Similarly, finding that more automobile
accidents occur during rush hour than at any
other time does not necessarily imply that it’s
more dangerous to drive during rush hour.
 It could be, but the greater number of
accidents may also occur simply because
that’s when so many people are driving their
cars.
 From sheer numbers alone, far more
windshield wipers are turned on during rush
hour than during any other time but that does
not mean that it rains more during rush hour.
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Perceiving Order in Random Events
 What may seem to be an extraordinary
event may have a chance-related
explanation.
 As Myers states, “An event that
happens to but one in 1 billion people
every day occurs about six times a day,
2000 times a year.”
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Perceiving Order in Random Events
 Random sequences often do not look
random.
 E.g., coin tosses, number occurrences
 When you don’t seem to think this coin
toss or string of numbers in the lotto is a
chance event. And that is what’s known
as the gambler’s fallacy.”
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Figure 1.3 Scatterplots, showing patterns of correlation
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers
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Figure 1.5 Three possible cause-effect relationships
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers
58
Experiment
 Is a research method in which the
investigator manipulates one or more
variables to observe their effect on
some behavior or mental process while
controlling other relevant factors.
 If a behavior changes when we vary an
experimental factor, then we know the
factor is having a causal effect.
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Random Assignment &
Double-Blind
 In many experiments, control is
achieved by randomly assigning
people either to an experimental
condition, where they are exposed to
the treatment, or a control condition,
where they are not exposed.
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Double-Blind
 Often, the research participants are blind
(uninformed) about what treatment, if any,
they are receiving.
 One group might receive the treatment, while
the other group receives a placebo (a
pseudotreatment).
 Often both the participant and the research
assistant who collects the data will not know
which condition the participant is in (the
double-blind procedure).
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Placebo Effect
 The placebo effect is well-documented.
Just thinking one is receiving treatment
can lead to symptom relief.
 However, the individual did not receive
the treatment.
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Variables
 The independent variable is the
experimental factor that is being
manipulated. It is the variable whose
effect is being studied.
 The dependent variable is the variable
that may change in response to the
manipulations of the independent
variable. It is the outcome factor.
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Figure 1.2 How to read a correlation coefficient
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers
64
Bar Graphs
 Bar graphs provide one way to organize and
present distributions of data.
 The visual display permits comparisons
between different groups on the same
quantitative dimension.
 Reducing or expanding the range of that
measure can make differences between
groups appear smaller or larger. It is always
important to read the scale labels and note
the range.
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Three Measures of Central
Tendency
 Mode: is the most frequently occurring score
in a distribution.
 Mean: is the arithmetic average of a
distribution, obtained by adding the scores
and then dividing by the number of scores. It
is biased by a few extreme scores.
 Median: is the middle score in a distribution;
half the scores are above it and half are
below it.
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Two Measures of Variation
 The range of scores—the gap between the
lowest and highest score—provides only a
rough estimate of variation.
 The more standard measure of how scores
deviate from one another is the standard
deviation. It better gauges whether scores
are packed together or dispersed because it
uses information from each score.
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Important principles to remember in
making generalizations
 Representative samples are better than
biased samples. We are particularly prone to
overgeneralize from vivid cases at the
extremes.
 Less-variable observations are better than
those that are more variable. Averages are
more reliable when derived from scores with
low variability.
 More cases are better than fewer. Small
samples provide less reliable estimates of the
average than do large samples.
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When are Differences
Meaningful?
 Tests of statistical significance to help
them determine whether differences
between two groups are reliable.
 When the averages of the samples
drawn from the groups are reliable, and
the difference between them is large,
we say the difference has statistical
significance.
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 This means that the difference very
likely reflects a real difference and is
not due to chance variation between
the samples.
 Given large enough or homogeneous
enough samples, a difference between
them may be statistically significant yet
have little practical significance.
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Laboratory Experiments
 The experimenter intends the laboratory
experiment to be a simplified reality, one in
which important features can be simulated
and controlled.
 The experiment’s purpose is not to re-create
the exact behaviors of everyday life but to test
theoretical principles.
 It is the resulting principles—not the specific
findings—that help explain everyday
behavior.
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Generalizing Findings
 Although culture shapes our specific
attitudes and behaviors, the principles
that underlie them vary much less.
 Our shared biological heritage unites us
as members of a universal human
family.
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 Studying gender differences is not only
interesting but also potentially beneficial
in preventing conflict and
misunderstanding in everyday
relationships.
 It is important to remember, however,
that psychologically as well as
biologically, women and men are
overwhelmingly similar.
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Statistics
 Statistics help us to organize,
summarize, and make inferences from
data.
 They enable us to evaluate big, round,
undocumented numbers that often
misread reality and mislead the public.
 Statistics help us to see what the naked
eye misses.
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Describing Data
 Statistics help us to organize,
summarize, and make inferences from
data.
 They enable us to evaluate big, round,
undocumented numbers that often
misread reality and mislead the public.
 Statistics help us to see what the naked
eye misses.
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Making Inferences
 The temptation to generalize from a few
unrepresentative but vivid cases is
nearly irresistible.
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Differences Between Groups
 The need for two sample groups can be
readily overlooked. Without having
comparison groups, we are unable to
evaluate the claims. In other cases, we
may not know whether the comparison
group is appropriate.
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Differences Between Groups
 A detergent manufacturer claims that its
dishwashing liquid has been found to be 35
percent more effective. Should you switch to
its brand?
 A major corporation proudly claims that its
profits have increased 150 percent over
those in the previous year. Should one rush
out and buy its stock?
 In each case, we cannot make an informed
judgment without knowing the nature of the
comparison group.
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Can Laboratory Experiments Illuminate Everyday Life?
 In an attempt to overcome the
artificiality of the laboratory
environment, some researchers
conduct field experiments. For example,
do the race and sex of a person who
requests help influence our generosity?
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Research
 Some psychologists study animals out
of an interest in animal behaviors.
 Others do so because knowledge of the
physiological and psychological
processes of animals enables them to
better understand the similar processes
that operate in humans.
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 Because psychologists follow ethical
and legal guidelines, animals used in
psychological experiments rarely
experience pain.
 The debate between animal protection
organizations and researchers has
raised two important issues: Is it right to
place the well-being of humans above
that of animals, and what safeguards
are in place to protect the well-being of
animals in research?
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 Ethical principles for the treatment of
human participants urge investigators to
obtain informed consent, protect
subjects from harm and discomfort,
treat information about individuals
confidentially, and fully explain the
research afterward.
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Research Ethics
 Stanley Milgram’s studies of obedience (see
Chapter 18), which heightened awareness of
the problems of deception in research and of
psychological harm to participants.
 Practically all the ethical issues reflect a
conflict between the rights of the individual
and the possible benefits of the research to
society.
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Research Ethics
 Psychologists have typically applied a
cost-benefit analysis.
 Does the potential benefit of the study
to society outweigh the potential costs
to participants?
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Personal Values Can
Influence
 Psychologists’ values can influence
their choice of research topic, their
theories and observations, their labels
for behavior, and their professional
advice.
 Knowledge is power that can be used
for good or evil.
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Personal Values Can
Influence
 Our preconceptions bias our observations
and interpretations (e.g., assessment data,
recommendations)
 Values also penetrate the theories proposed
by psychologists.
 Perhaps the most seductive error is to
translate one’s description of what is into a
prescription of what ought to be (naturalistic
fallacy. (e.g., Kohlberg’s highest level few
ever reach
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 Applications of psychology’s principles
have so far been mostly for the good,
and psychology addresses some of
humanity’s greatest problems and
deepest longings.
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