THINKING CRITICALLY WITH PSYCHOLOGICAL SCIENCE

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Critical Thinking- the ability and willingness to assess claims and make objective judgments on the basis of well-supported reasons and evidence.

Critical thinkers are able to look for flaws in arguments, resist claims that lack supporting evidence, and recognize that criticizing an argument is not the same as criticizing a person.

THINKING CRITICALLY WITH PSYCHOLOGICAL SCIENCE

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Eight guidelines emphasized by the text:1. Ask questions- Be curious and willing to ask why.2. Define your terms- Be clear, concrete and precise3. Examine the evidence- Use reliable resources and

empirical evidence4. Analyze assumptions and biases- Analyze and test beliefs

(yours and others) that may be taken for granted5. Avoid emotional reasoning- question your support for an

argument…is it based in evidence6. Don’t oversimplify- gather multiple sources of supporting

evidence and do not generalize7. Consider other interpretations- even after generating a

possible explanation be willing to accept other possibilities8. Tolerate uncertainty- It may be difficult if not impossible to

determine an absolute answer and that’s okay

ASKING QUESTIONS…. With hopes of satisfying curiosity, many

people listen to talk-radio counselors and psychics to learn about others and

themselves.

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Dr. Crane (radio-shrink)

http://ww

w.nbc.com

http://ww

w.photovault.com

Psychic (Ball gazing)

CRITICAL THINKING

Critical thinking does not accept arguments and

conclusions blindly.

It examines assumptions,

discerns hidden values, evaluates

evidence and assesses

conclusions.

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The Amazing Randi

From The Secrets of the Psychics

Courtesy of the Jam

es Randi E

ducation Foundation

CRITICAL THINKING LEADS TO A SCIENTIFIC ATTITUDE

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The scientific attitude is composed of curiosity (passion for exploration), skepticism (doubting and questioning) and humility (ability to accept responsibility when wrong).

THE NEED FOR PSYCHOLOGICAL SCIENCE

Intuition & Common Sense have limits

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Many people believe that intuition and common sense are enough to bring forth

answers regarding human nature.

LIMITS OF INTUITION

Personal interviewers may rely too much on their “gut feelings”

when meeting with job applicants.

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Taxi/ Getty Im

ages

ERRORS OF COMMON SENSE

Try this !

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Fold a piece of paper (0.1 mm thick) 100 times. How thick will it be?

800,000,000,000,000 times the distance between the sun and the earth.

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.

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OVERCONFIDENCESometimes we think we know more than we actually know.

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Anagram

BARGEGRABE

ENTRYETYRN

WATERWREATHow 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).

PSYCHOLOGICAL SCIENCE HOW DO PSYCHOLOGISTS EXPLAIN UNSEEN MENTAL PROCESSES? HOW DO THEY DIFFERENTIATE BETWEEN OPINIONS AND EXAMINED CONCLUSIONS?

By using the Scientific Method as the basis for psychological research examined

conclusions can leads to a clear understanding of how people feel,

think, and act as they do! 11

SCIENTIFIC METHOD

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Collect Data/Make Observations

Generate an initial theory based on research

RESEARCH PROCESS

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ASK QUESTIONS

The Scientific Method begins with wondering: What? Why? Or How?

In the example of depression…the psychologist may have wondered what

is the relationship between low self-esteem and depression

THEORY

A Theory is an explanation that integrates principles, organizes events

and predicts behavior based on empirical evidence.

For example, low self-esteem possibly contributes to depression.

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HYPOTHESIS

A Hypothesis is a testable prediction, often prompted by a scientific attitude, to enable us to accept, reject or revise a

theory.

If people have low self-esteem then they are apt to feel more depressed.

(Note: The If/Then statement)

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RESEARCH OBSERVATIONS

Research would require us to administer tests and make further observations to

confirm or deny a hypothesis

In our example…Individuals who score low on a self-esteem test and high on a

depression test would confirm our hypothesis.

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THREE TYPES OF (BASIC) PSYCHOLOGICAL RESEARCH

Descriptive Correlational Experimental

PSYCHOLOGICAL RESEARCH

Descriptive Research

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The purpose of this type of study is to describe and predict behaviors.

VARIOUS DESCRIPTIVE METHODS INCLUDE:

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BEHAVIORAL OBSERVATION:Case Study

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A technique in which one person or a small group is studied in depth to reveal

underlying behavioral principles. The study of this one individual may include an individual history, careful observation

and/or psychological testing.

Do animals have language?

Susan K

uklin/ Photo R

esearchers

COVERT BEHAVIORAL OBSERVATION:NATURALISTIC OBSERVATION

Naturalistic observation involves the observation, recording and measurement of behavior without

intrusion into the subjects natural or normal environment.

Observing and recording the behavior of animals in the wild and recording self-seating patterns in a

multiracial school lunch room constitute naturalistic observation. 22

Courtesy of G

ilda Morelli

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OVERT BEHAVIORAL OBSERVATION:LABORATORY OBSERVATION

Observing and recording the behavior of animals and people in a controlled

environment enables the scientist to use more sophistic devices for measurement.

However, this environment may lead to participants acting differently because they

are in unusual surroundings.

BEHAVIORAL OBSERVATIONS:PSYCHOLOGICAL TESTS OR INSTRUMENTS

Psychological tests, also called assessment instruments, are procedures for measuring and

evaluating a wide variety human traits, emotional states and behaviors.

Typically, tests require a response to a series of questions that can be scored and used for statistical analysis.

PRINCIPLES OF TEST CONSTRUCTION

For a psychological test to be acceptable it must fulfill the following three criteria:

1. Standardization

2. Reliability3. Validity

STANDARDIZATION

Standardizing a test involves administering the test to a representative sample of test

takers in order to establish a basis for meaningful comparison (a norm) and to

establish appropriate test procedures that can easily be duplicated.

RELIABILITY

A test is reliable when it yields consistent results. To establish reliability researchers

establish different procedures:

1. Split-half Reliability: Dividing the test into two equal halves and assessing how consistent the scores are.

2. Reliability using different tests: Using different forms of the test to measure consistency between them.

3. Test-Retest Reliability: Using the same test on two occasions to measure consistency.

VALIDITY

Reliability of a test does not ensure validity. Validity of a test refers to what the test is

supposed to measure or predict.

1. Content Validity: Refers to the extent a test measures a particular behavior or trait.

2. Predictive Validity: Refers to the function of a test in predicting a particular behavior or trait.

SELF REPORTS:SURVEY

A technique for ascertaining the self-reported attitudes, opinions or behaviors

of people. This is usually done by questioning a representative sample that

is both random and proportional.

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http://ww

w.lynnefeatherstone.org

REPRESENTATIVE SAMPLEIt is impossible to survey everyone in

any given population. It is necessary therefore to survey a group of individuals that accurately represents the larger population being studied.

The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.

SURVEY

Random Sample -ensures that everyone

in the larger population has an

equal chance of being selected as part of the representative

sample. If the survey sample is not random it may be biased and its results would not

be valid.31

Random Sampling

Errors in Random Sampling

Volunteer Bias- People who volunteer may feel more strongly than those who do not.

Selection Bias- If selection of participants are not random…the order of selection may bias results

PROPORTIONAL

The sample must represent an accurate proportion of the variations in the larger population in order to be a true representative sample.

For Example: The sample should include the same percentage of males and females as what would be found in the larger population.

SURVEY

Wording can change the results of a survey.

Q: Should cigarette ads and pornography be allowed on television? (allowed vs. forbidden)

Q: How many times in your life have you “cheated”?

(Have you ever? vs. How many? And cheated vs. lied or been dishonest)

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Wording Effect

SURVEY

A tendency to overestimate the extent to which others share our

beliefs and behaviors.

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False Consensus Effect

PSYCHOLOGICAL RESEARCH

Correlational Research Correlation and Causation Illusory Correlation Perceiving Order in Random

Events

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CORRELATION

Correlation Coefficient is a statistical measure of the relationship between two

variables.36

When 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+

SCATTERPLOTS

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Perfect positivecorrelation (+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

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No relationship (0.00)Perfect negativecorrelation (-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

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Data showing height and temperament in people.

SCATTERPLOT

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The Scatterplot below shows the relationship between height and

temperament in people. There is a moderate positive correlation of +0.63.

CORRELATION AND CAUSATION

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or

ILLUSORY CORRELATION

The perception of a relationship where no relationship actually exists. Parents conceive

children after adoption.

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Confirming evidence

Disconfirming evidence

Do not

adopt

Disconfirming evidence

Confirming evidence

Adopt

Do not conceiveConceive

Michael N

ewm

an Jr./ Photo Edit

ORDER IN RANDOM EVENTS

Given random data, we look for order and meaningful patterns.

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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.

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Angelo and Maria Gallina won two California lottery games on the same

day.

Jerry Telfer/ San F

rancisco Chronicle

PSYCHOLOGICAL RESEARCH

Experimental Research Exploring Cause and Effect Evaluating Therapies Independent and Dependent

Variables

EXPERIMENTATION

Like other sciences, experimentation is the backbone of psychology research. The purpose of experimental research is to

isolate causes and their effects.

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 factors manipulated by a researcher isolate cause and effect

relationships.

MANIPULATED SOME FACTORS WHILE OTHERS ARE KEPT IN CONTROL….

I manipulated whether students had candy to eat while taking a quiz. These students were the experimental group

Students who did not receive a candy were the control group, because their testing condition was the same as it normally is.

RANDOM ASSIGNMENT

Assigning participants to experimental (candy eating) and control (non-candy eating) conditions by

random assignment minimizes pre-existing differences between the two groups.

Students were randomly assigned to either the experimental or the control group based on the row in which they sat within the classroom. If a student

refused the lollipop it was given to the nearest student in the next row.

If I gave candy to the first 15 students who came to class or students in the front of the room, a pre-

existing difference may have accounted for a difference in test scores.

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

candy on test scores, candy 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 candy on test scores, test scores are the

dependent variable. The score on the assessment is dependent on whether or not

a candy was eaten

A SUMMARY OF STEPS DURING EXPERIMENTATION.

Random Assignment: Students are given lollipops by row

Condition Independent Variable

Dependent Variable

Experimental

Control

Scores from a 8 point

memory task

No sweet substance

made primarily of sugar

A sweet substance

made primarily of sugar

Scores from a 8 point

memory task

EXPERIMENTER EFFECTS

Expectations can influence results!

My hypothesis was clearly written on the board when students were taking the test and eating candy. Their expectation that they would or would not perform well could have influenced your actual

performance.

Because of this, psychologists use single blind procedures. Where the participant is unaware of the

behavior being observed.

SINGLE-BLIND PROCEDURE

In a single blind study, participants would not know whether they are in the experimental

or control group.

Psychologists may use a placebo to keep participants unaware of any differences in

their treatment.Placebo- an inactive substance or fake

treatment used as a control in an experiment or given by a practitioner to a patient

DOUBLE-BLIND PROCEDUREParticipants are not the only people to bring expectations to the laboratory. Experimenter

Effects can have powerful results

In setting up the experiment and evaluating results, the participants and the experimenter’s

assistants conducting the experiment should both remain unaware of which group was the

experimental group and which was the control.

Think of the Russian scientists conducting the research on psychic ability.

INTERPRETING RESULTS

If an experiment is repeated and consistently yields the same results, the finding can be deemed reliable.

However, the best interpretation of a finding does not emerge until the hypothesis is further tested in multiple ways.

So, after repeating my candy experiment several times…I may want to change the type of candy, assessment or student to see if that has an impact on my result

THINKING CRITICALLY …

Statistical Reasoning Interpreting Results Describing Data Making Inferences

DESCRIBING DATA

A meaningful description of data is important in research. Misrepresentation

may lead to incorrect conclusions. Statistical procedures analyze and

interpret data allowing us to see what the unaided eye misses.

MEASURES OF CENTRAL TENDENCYA GOOD WAY TO SUMMARIZE DATA IS TO USE ONE OF THE FOLLOWING MEASURES OF CENTRAL TENDANCY

Mode: The most frequently occurring score in a distribution.

Mean: The arithmetic average of scores in a distribution obtained by adding the scores and then dividing by the number of scores that were added together.

Median: The middle score in a rank-ordered distribution.

MEASURES OF CENTRAL TENDENCY

A Skewed Distribution

EXPERIMENTAL RESEARCH METHODCANDY EXPERIMENT DATA COLLECTION

Candy Rows (Experimental Condition) 10 Students

2,5,5,5,6,7,8,8,8,8

Mean 6.2/10Median 6.5/10Mode 8/10

Non-candy Rows (Control Condition) 16 Students

3,4,4,4,5,5,6,6,6,6,6,6,7,7,8,8

Mean 5.3/16Median 6.5/16Mode 6/16

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.

D. Shapiro, © Wildlife Conservation Society

FAQ

Q5. Is it ethical to experiment on animals?

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.