thinking critically with psychological science. to be human is to be curious… o everyday we say: o...
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Thinking Critically with Psychological
Science
To be human is to be curious…
O EVERYDAY we say:O “why did she say that?” O why did he behave that
way?”
O Psychologists say:
O “What is the use of SAT scores?
O How do we diagnose ADHD?
O Does specific gene cause obesity?
O After asking these questions psychologists must decide which research technique or procedure will help them to best answer their question.
Why do people turn to
psychology?
Satisfying their own Curiosity…
Remedy their own woes…
Intrigued by claims of psychological truths…
Intrigued by claims of psychological truths: can we
trust the claim that childhood sexual abuse memories get
“recovered in adulthood
How can we best use psychology to understand why
people think, feel and act as they do?
Need for Psychological Science
O Most people think that psychology merely documents and dresses in jargon of what people already know
O Some people think human intuition is where we should put our trust and faith in…
O HOWEVER we operate on two levels, conscious and unconscious, and most of the time we are operating automatically on autopilot
O Psych experiments have shown that people overestimate their lie detection accuracy, eyewitness testimony, their risks, predictions and many other things
O Autopilot…Autopilot… as you will learn, our thinking, memory, & attitudes operate largely on automatic processing, (unconsciously)
Hindsight Bias: I knew it all along phenomenon
O We find it so easy to seem insightful when drawing the bull’s eye after the arrow has struck
O Ex: world trade centerO Finding that something happened
makes it seem inevitable, a tendency we call hindsight bias (I knew it all along phenomenon)
O Ex: Romantic Attraction study Demonstrated: giving half member of a group some bogous “psychological finding” and give the other half the opposite result nearly all regard this ”true finding” as unsurprising common sense!!
Pg. 17
Why we need psychological science….
these errors in our recollections that show why we need psychological science…
O Just asking people how they feel or acts as they did can sometimes be misleading because common sense describes what happened not what will happen
O Hindsight bias is widespread studies reported it is found in various countries an among both children and adults
O We are all behavior watchers and it would be surprising is psychology’s findings has not been forseen (according to those who say their grandma already knew that)
O
OverconfidenceO As humans we tend
to be overconfidentO We tend to think we
know more than we do
O When asked how sure we are of our answers to factual questions we tend to be more confident that correct
O Ex: WREATWATER
What do you think?O How many seconds
do you think it would take you to solve these?
O WREATO ETRYNO GRABEO OSCHA
OVERCONFIDENCEHindsight seems so obvious that people become over confident
O Goranson 1978 asked people to unscramble the words, average took 3 minutes to unscramble but they think they would have the solution in only 10 seconds
O Average answer = 10 seconds, average solved = 3 minutes
O Once people know the answer hindsight bias seems obvious so much that we become over confident
O Point to remember: hindsight bias and overconfidence often lead us to overestimated intuition BUT scientific inquiry can help us sift reality from illusion
O SCIENTIFIC RESEARCH CAN SHIFT FORM ILLUSION TO REALITY
3 component of Sci. Attitude: The empirical approach
O 3 main components:O Curiosity: passion to explore and
understand without misleading or being mislead
O Ex: does it work? When put to the test can its predictions be confirmed?
O EX: James RandiO Skepticism: curious skepticism not
cynical, open but not gullible:O What do you mean? How do you
know?O Putting claims to the test
O Humility: awareness to our own vulnerability to error and openness to surprises and new perspectives:
O What matters are the truths nature reveals not opinions
O “the rat is always right”
How to Think CriticallyO Critical thinking:O Thinking that does not blindly
accept arguments or conclusionsO scientific attitude prepares us to
think smarterO examines assumptions, discerns
hidden values, evaluates evidence, and assess conclusions
O EX:O how do they know that?O What is this persons agenda?O Is the conclusion based on
anecdote and gut feelings or evidence?
O Does the evidence justify a cause and effect conclusions?
O What alternative explanations are possible?
Psychological Science
1. How can we differentiate between uninformed opinions and examined conclusions?
2. The science of psychology helps make these examined conclusions, which leads to our understanding of how people feel, think, and act as they do!
Scientific Attitude needs the Scientific Method…
Psychological science evaluates
competing ideas with careful observation and analysis
In an attempt to describe and explain human nature it
welcomes everyday hunches and theories & puts them to
the test…
Psychologists, like all scientists,
use the scientific method to construct theories that
organize, summarize and simplify observations.
The science of psychology
O Scientific Method:O is an approach to
gathering information and answering questions so that errors and biases are minimized
O In psychology conclusions are based on data that support predictions; data can come from experiments, surveys, case studies.
1
. Observe the behavior/Identify the problem or questions (describe)
2. Formulate a hypothesis (explain)
3. Collect data through observation and experimentation (predict)
4. Analyze the data collected
5. Formulate a theory (control/influence)
Theories & HypothesesO theory:
O explains though an integrated set of principles that organizes observations and predicts behaviors or events
O A theory simplifies by organizing and simplifyingO Ex: facts & observations & their linksO For example, low self-esteem contributes to depression.
O Hypotheses:O Good theory produces testable predictions call hypotheses Testing and rejecting
or revising theories allows these predictions to give direction to research; they specify what result would support the theory and which would disconfirm it
O Can lead to subjective observations: seeing what we expectO People with low self-esteem are apt to feel more depressed.
O Operational Definitions:O Used to check on biases of psychologists; thus they will report their research with
precise operational definitions of procedures & conceptsO Ex: “hunger” reported as “hours without eating”O Generosity money donated
O Replication: O Operational definitions allow for researches to recreate the study if replication
studies produce similar results then our confidence in finding reliability grows
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
methods of researchO Descriptive Methods:
O Includes: case studies, surveys, & natural observations, correlations
O Correlational methods:O Associations of
different factorsO Experimental methods:
O Manipulating factors to find cause & effect
Descriptive ResearchO Any research that observes and records.O Does not talk about relationships, it just
describes.
What is going on in this picture?
We cannot say exactly, but we can describe what we see.
Thus we have…..
Naturalistic Observation
A descriptive method that observes & records behavior in natural occurring settings without trying to manipulate or control the situation Ex: watching chimps in the
jungle to videotaping parent child interactions, recording seating patterns in lunch room
Only describes behavior does not explain it
Opens up ways for further studies & illuminates human behavior
Case Studies Descriptive; An observation technique in which one
person is studied in depth in the hope of revealing universal truths
Ex: studies on impairments after brain damage in certain areas has led our knowledge of the brain
O Advantage: very revealing, give direction for further study, show what can happen
O Disadvantage = gives detailed information about one person & can’t be generalized to the larger population; unrepresentative info can lead to false conclusions & mistaken judgments
Dramatic stories & personal testimonies command out attention BUT are usually atypical “well I have a cousin that…”
Point to remember: CS give a glimpse & ideas for future study but to find truths we must use other research methods
SurveysO Descriptive Technique used to discover self reported
attitudes or behaviors of a particular group usually by questioning a representative random sample of the group
O AdvantagesO Looks at many cases in less depth, cheap, lots of information
fast from a large number of peopleO Asking questions = tricky & answers depend on way
questions are worded & respondents chosen
Disadvantage: Wording effects: subtle changes can influence the
respondents answer/opinions Q: Should cigarette ads and pornography be
allowed on television? (not allowed vs. forbid)
Can be biased answers: People don’t give truthful answers Give socially acceptable answers: Unrepresentative sample
Findings from natural
observations
Humans laugh 30 times more
often in social situations that in solitary situations
Life is fastest paced in Japan &
Western Europe and slower paced in economically less
developed countries
People in colder climates tend to live faster paced
Surveys & natural observations
Offer snapshots of everyday life
but without controlling for what is influencing behavior
Natural observations and surveys are descriptive
methods of research that can
provide data for correlational research
Describing behavior is the first step in predicting it
Surveys & Natural observations often show us how one
behavior is related to another…
PopulationO Population: who you are
studying: the whole group you want to study and from which your samples will be drawn
O Ex: women, men, Americans, teenagers, elderly, preschool children, Chinese, young adults, teenagers in los Angeles
O We must first decide who we want to study, then take a representative sample from that population under investigationO B/C WE CANT STUDY EVERY
SINGLE INDIVIDUAL
Correlational ResearchO Detects relationships between variables.O Does NOT say that one variable causes
another.
There is a positive correlation between ice cream and murder rates. Does that mean that ice cream causes murder?
Correlations
O Correlation:O A measure of the extent to which two factors
vary together and thus how well either factor predicts the other
O An association
Correlation coefficient: A statistical measure of the relationship
between the two things; (from -1 to +1) Tells how closely two things vary together &
thus how one predicts the other Ex: knowing how much aptitude test scores
correlate with schools success tells us how well the scores predicts school success.
Scatterplots: O graphed cluster of dots, each of which
represents the values of the two variables; the slope of the point suggests the direction of the relationship between the two variables; the amount of the scatter suggests the strength of the relationship.
Positive & negative positive correlation: means
that as one event increases, the second event tends to increase; the two sets of scores rise and fall together◦ the more hours spent
studying, the higher/better the grade
◦ Height & weight negative correlation:
means that as one event tends to increase, the other event tends to decrease; two scores relate inversely, as one rises the other falls
Toothbrushing & decay
◦ the number of hours you spend practicing shooting three pointers, the less likely you will be to miss them
CorrelationWhen one trait or behavior accompanies
another, we say the two correlate.
Correlation coefficient
Indicates directionof relationship
(positive or negative)
Indicates strengthof relationship(0.00 to 1.00)
r = 0.37+
Correlation Coefficient is a statistical measure of the relationship between two
variables.
ScatterplotThe Scatterplot below shows the relationship between height and
temperament in people. There is a moderate positive correlation of +0.63.
ScatterplotThe Scatterplot below shows the relationship
between height and temperament in people. There is a moderate positive correlation of +0.63.
or
Correlation and Causation
Correlation does not mean causation!
Illusory CorrelationsO Perceived but nonexistent
correlationO The perception of a relationship
where no relationship actually exists. Parents conceive children after adoption.
O Ex: people conceive after adoption
O can you think of some?O Superstitions?O When believe there is a
relationships we tend to notice and recall instances that confirm our belief
O Random coincidences = Just random
Order in Random Events
O Given random data, we look for order and meaningful patterns.
O Given large numbers of random outcomes, a few are likely to express order.
O Ex: Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
Survey Random Sampling
O 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.
O For an accurate picture of a whole population’s attitudes & experience we need a representative sample…
O Ex: a representative sample of students at your school or American male shoe size
O In order to generalize our results we need a representative sample from the population
O Cant compensate for unrepresentative sample by adding more people
O w/o random sampling we would give misleading results
With a representative sample Now we can generalize our findings from the sample experimented on to the population we are attempting to study
The fastest way to know about the marble color ratio is to blindly
transfer a few into a smaller jar and count them.
Lab
Experimentation
Remember information from surveys, case studies, and natural observations
have potential for bias and error & the information
gained cannot determine cause & effect
To find the cause of effect of events we must
experiment…
Experimentation
O Like other sciences, experimentation is the backbone of psychological research. Experiments isolate causes and their effects.
O ExperimentsO (1) manipulate factors that interest us,
while other factors are kept under O (2) control.O Effects generated by manipulated factors
isolate cause and effect relationships.
Exploring Cause and Effect
What is an experiment?O Research method in
which an investigator manipulates one or more variables (independent variable) to observe the effect on a behavior or mental process (dependent variable)O variable: anything that
can vary– intelligence, TV exposure, nutrition)
Steps of experimentation
1. Ask: a research question2. Form a hypothesis3. Identify the variables: independent & dependent4. Choose participants5. Randomly Assign participants: experimental &
control groups6. Conduct the experiment: Manipulate the
Variables: independent & dependent7. Measure effects of independent variable on
dependent variable8. Analyze results with statistical procedures
Identify Variables
Independent variable
Dependent Variable
O Experimental factor that is manipulated; the variable whose effect is being studiedO ex: drug dosageO Ex: # hours sleptO Ex: amount of coffee
O Measureable behavior; outcome factor; the variable that will change in response to the manipulations of the independent variableO Ex: Decreased
symptomsO Ex: Test performanceO Ex: Performance on
reaction times
The variablesO Both variables are given precise
operational definitions, which specify the procedures that manipulate the independent variableO Ex: the amount of drug dosageO Ex: the timingO These definitions answer: “what do
you mean by that?”O Ex” what do you mean by drugs taken”
Your turn…Identify the IV & DV: Please match up as many scenarios as
you can, putting the DEPENDENT VARIABLE FIRST, and then describing what affected it (the independent)
Ex. (DV) Increased weight loss was affected by (IV) hours you run per week.
increased weight loss The number of hours a person sleeps, Taking vitamins, increased energy and well being Eating healthy foods and exercising, Working with someone more fit, test performance Hours you run per week, increased pace of your own workout increased cardiovascular health
Confounding variablesO Other factors that can potentially
influence the results of the experimentO Age, education, socioeconomic
status, weight, environment
O Random assignment controls for possible confounding variables
Choosing participants: Random Assignment
1. Participants from the population being studied are randomly selected to participate
2. What is random selectionO Participants are randomly assigned to one of two
groups: to experimental and control groups by chance, minimizing preexisting differences between those people assigned to the different groups
O Participants are blindly assigned to these groups, meaning they are uninformed about what treatment (if any) they are receiving
O This Allows researchers to hold constant all factors except for the one they are manipulating
O Eliminates alternative explanations for findings
2 groups:O Experimental group:
O the group that is exposed/receives to the treatment (exposed to the IV)
O Control group/comparison group:O group that is not exposed to the
treatment (IV); contrasts with the experimental group & serves as a comparison for evaluating the effect of the treatment
Problems & solutions in Research
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Self fulfilling prophecies
Placebo effects
Placebo Effect
Sometimes just thinking you are
getting a treatment can boost
your spirits, relax your body, or relieve your symptoms…
This placebo effect is well documented in reducing pain,
depression, and anxiety…AND the
more expensive the drug the more real we think it is…
Placebo EffectO To know how effective a
therapy is, researchers must control for a possible placebo effect
O Placebo: O some intervention:
taking a pill, receiving and injection, or undergoing an operation that resembles medical therapy but has no medical effect.
O Placebo effect:O A change/effect
on a participants illness or behavior that results from an imagined treatment rather than to a medical/actual treatment
The effect… Researchers believe that
placebos work by reducing tension and distress and by creating powerful self-fulfilling prophecies so that individuals think and behave as if the drug is actually affective
35-75% of patients benefit from taking placebos for a variety of problems: pain, depression, headaches
How can it be avoided for research purposes?
Double blind experiment
O An experiment in which neither the participants nor the experimenters know which group received the treatment (which gets the drug and which gets the placebo)
O Eliminates the possibility the researcher will unconsciously find what he/she expects about the effects of the drug
O Allows researchers to check actual effects of treatment rather than participants beliefO Ex: FDA
Single blind experimentsO Single Blind
ExperimentO An experiment in
which the participants are unaware of which participants received the treatment
O Participants are “blind” in the sense that they don’t know if they get the drug or placebo “blindly” assigned to
the Experimental group or control group
Stanley Milgram’s Electric Shock
Experiment
What happened????
Statistical ReasoningStatistical procedures analyze and interpret data allowing us to see what the
unaided eye misses.
Once researchers have collected all their data, how are they supposed to organize it so that it makes sense?
They need to figure out how they can organize it so that they can analyze it to see whether their findings support or contradict their hypothesis.
White63%
Black16%Hispanic
10%Asian
7%
Others4%
Composition of ethnicity in urban locales
Statistics:O Statistics: branch of
mathematics concerned with summarizing and making meaningful inferences from collections of dataO 2 types used in
psychology: descriptive & inferential
O Often misread and thus mislead the public…doubt big rounded numbers!!!
Descriptive statisticsO Descriptive
Statistics: listing and summarizing of data such as using graphs and averagesO Frequency
distributions, bell curves, central tendency, variability, correlation coefficients
Descriptive Statistics
Central tendencyO Central tendency refers to how the data
measure the center of a set of data; the mean, median, and mode all point to where the middle of the data should be
O Mode: most frequently occurring score in a distribution
O Mean: arithmetic average of scores in a distribution obtained by adding the scores and then dividing by the number of scores that were added together.O Is the most affected by extremes scores in
the data
O Median: midpoint; 50th percentile; The middle score in a rank-ordered distribution.
O Measures of central tendency neatly summarize data
Measures of Central Tendency
A Skewed DistributionWhat is skewed? If the mean, median, and mode are all the same number, the graph of the data will look like a normal curve; if they are all different the graph will be skewed or off center in some way
Positively skewed: occurs when scores pull the mean toward the higher end of scores (the mean is more positive or greater than the rest of the scores)Negatively skewed: occurs when scores pull the mean toward the lower end of scores
Measures of VariationMOV ask: How similar or diverse are scores?
Variation: how similar or diverse the scores in the data set areO Averages taken from scores with low variability are more reliable than
averages taken from scores with high variability
Range: The difference between the highest and lowest scores in a distribution.
Standard Deviation: A measure of how much scores vary around the mean score( how close or far scores are from the mean); the higher the SD the less similar the scores are; you want a smaller SD because you are able to draw more stable conclusions from the data set
O Ex: university score of intelligence vs larger community college of more diverse scores
O Scores most often form bell shaped curve= Normal curve
Standard Deviation
Normal curveO Normal curve:
symmetrical bell-shaped curve that describes the distribution of many types of data (normal distribution)
O Most scores fall near the meanO Ex: 68% fall within one
standard deviation of mean on either side; fewer and fewer at extremes
Illusion of Control
1. Illusory Correlation: the perception of a relationship where no relationship actually exists.
2. Regression Toward the Mean: the tendency for extremes of unusual scores or events to regress toward the average.
That chance events are subject to personal control is an illusion of control fed by:
Inferential statisticsO Inferential Statistics: method
used to determine whether research data supports the hypothesis or whether results are due to chance;
O Making an Inference: A statistical statement of how frequently an obtained result occurred by experimental manipulation or by chance.
O Use stats to make generalizations about the population based on the findings of the study
O Use statistical testsO Determine probability/chanceO Determine statistical
significance
Reliability & ValidityO Reliability: the extent to which a test yields consistent
results; based on the consistency of scores on two times or halves of the test(consistent scores)
O If the two scores agree or correlate then the test is reliable
O Validity: the extent to which the test actually measures or predicts what it says it is measuring O Content validity: tests measures what they are
supposed to measureO AP Psych exam should cover what we learned
O Predictive validity: a test should predict what it is supposed to predictO Ex: drivers test, SAT
Making Inferences: Reliability
1. Representative samples are better than biased samples.
1. Never extremes/never whole population sampled
2. Less-variable observations are more reliable than more variable ones.
3. More cases are better than fewer cases.1. Averages should be based on many
cases2. Generalizations that are based on few
cases are UNRELIABLE
When is an Observed Difference Reliable?
Statistical SignificanceO When is a difference significant?
O When sample averages are reliable & the difference between them is relatively large, we say the difference has statistical significance. It is probably not due to chance variation.
O Means the observed difference is probably not due to chance variation between the samplesO Odds of occurring by chance are
less than 5%O P score: indicates statistical
significance <.05, or .0001
Lab Experiements vs Reality
O Intended to be simplified reality; stimulates & controls features of everyday life
O Not recreating but testing theoretical principles
O Resulting principles not specific findings that help explain behavior
Ethical issues: animal testing
O Study them to learn how different species think, learn & behave; BUT also to learn about people
O Experiments have led to:O insulin, vaccines,
transplantsO Respect them for similarities,
protect them from sufferingO Protestors: against completely,
only observationsO Animals used for research only
1%O Issue: research has led to many
findings, treatments and cures
Ethical issue: PeopleO Ethical principles
developed by the American Psychological Association 1992
O 1. informed consent of participants
O 2. protect from harm & discomfort
O 3. confidentialityO 4.debriefing
Does lab experiments illuminate
everyday life????
O An experiment’s purpose is not to recreate exact behaviors but test psychological principlesO Ex: aggression study:
pushing a button delivering a shock = not same as slapping someone in the face but principle is the same…
O It’s the principles not the exact findings that help explain everyday behavior
The Stanford Prison
Experiment
The infamous unethical experiment in the history of
psychology
What went wrong….?
Is it ethical to experiment on
people?
O In most psychological studies with human participants extremes of delivering shocks are uncommon
O Occasionally researchers do temporarily stress or deceive people BUT only when they believe it is essential to a justifiable endO Ex: controlling violent
behavior O Studying mood swingsO These experiments would
not work if participants knew beforehand participants could act accordingly or opposite of what they think is expected
Ethical Issues in Psychology
O In 1992 the American Psychological Association published a set of ethical principles…
O Informed consent of potential participants
O Must protect them from harm & discomfort
O ConfidentialityO Deception & Debriefing: must
fully explain experiment afterO Stanford Prison
ExperimentO Milgram Experiment
O The knowledge of psychology…O To some it is common sense
to others they are concerned it is becoming too powerfulO Yes it Can be used for good
or evil or to manipulate people….BUT…
O Although it has power to deceive its purpose is to enlighten: enhance learning, creativity, compassion, world problems of war, family crises, crime, prejudice= all which involve attitudes & behaviors