n I t roduction to the H istory and Science of
Psychology
Module 1
What is Psychology?
Psychology as a Science
From the beginning to the 1920s t he science of mental life
Wilhelm Wundt, Edward Brad Ti tchner, William James, Sigmund Freud
1920s to 1960s t he scientific study of observable behavior
John B. Watson, B. F. Skinner
TODAY t he scientific study of behavior and mental processes
Psychology of Today
The scientific study of behavior and mental processes
Scientific study: experimental analysis
Behavior: anything an organism does that we can observe and record
E.g., eating, sleeping, playing, sweating, talking
Mental processes: internal, subjective experiences we infer from behavior
E.g., sensations, perceptions, dreams, thoughts
Contemporary Psychology
Psychologys Big Debate
Nature versus Nurture
Nature vs. Nur ture- Darwin states that nature selects those t raits that best enable
t he organism to survive and reproduce in nature
Scenario:
The nature-only side states that personalities are inf luenced by genetic factors and
r emain consistent across the life span.
The nurture-only side states that we are all essentially the same at birth, and we
a re the product of our experiences
Experiences makes us who we are
Anything is possible
Psychologys Three Main Levels of Analysis: Bio-psychosocial Approach
Who are Psychologists ?
Clinical Psychology vs. Psychiat ry
Clinical Psychologists (Ph.D.): study, assess, and t reat t roubled people with
psychotherapy.
Psychiat r ists (M.D.): medical professionals who use t reatments like drugs and
psychotherapy to t reat psychologically diseased pat ients.
Medical psychologists (M.P clinical psychologists who have earned their masters
.):
degree in psychopharmacology and can prescribe psychot ropic medicat ions
Research Psychologists
Applied Psychologists
Th inking Cr it ically wit h Psychological Science
Module 2
The lim its of int uit ion & common sense
Remember, psychology is the scient if ic study of behavioral and mental processes
In other words, psychology evaluates ideas
t hrough observat ion and experimental analysis
HOW DOES PSYCHOLOGY COMPARE AGA I NST COM MON SENSE?
The Need for Psychological Research
Fallibility of intuition
H i ndsight Bias is a tendency to believe, after learning about an
o utcome, that we would have foreseen it (also know as the
Judgmental Overconfidence I l lusory Correlation
The Scientific Attitude
Cu r iosity, Skept icism, Hum ility
Cr it ical Thinking
The h indsight bias i s a tendency to believe, after learning about an outcome, that we
would have foreseen it.
Ex: We knew that the dot.com stocks would plummet,
only after they did.
Also known as the I knew it all along p henomenon
Overconfidence
Definition: As individuals we tend to think we know more than we actually do
Overconfidence
Psychological Science
Two reliable phenomenahindsight bias and j udgmental overconfidence and our
need for scientific inqui ry and critical thinking.
The Need for Psychological Research
Fallibility of intui tion
H indsight Bias (I knew i t all along.)
Judgmental Overconfidence
I llusory Cor relation
The Scientific Attitude
Curiosity, Skepticism, Humility
Critical Thinking
I l lusory Correlation: Does a stereotype exist?
A psychologist sought to discover whether research would support the stereotype
t hat females are more emotional than males.
The psychologist found 16 studies in which either males or females were observed to
be either quite emotional or non-emotional .
Review the next slide. You will be asked to indicate what these data suggest about
t he relationship between gender and emotionality.
Which conclusion do you agree with MOST?
A. Women were somewhat more l ikely to be emotional.
B. Women were slightly more l ikely to be emotional.
C. Women and men were equally l ikely to be emotional.
D. Women were slightly less l ikely to be emotional.
E. Women were somewhat less l ikely to be emotional.
Interpretation
Most people conclude that the overall results of these studies show that, in
comparison to men, women are slightly or moderately more likely to be emotional.
That is an i l lusory correlation--that is, seeing a relationship where none exists.
In comparison to men, women were neither more nor less likely to be emot ional.
Can you ident ify other popular beliefs that may reflect illusory correlat ions?
The Need for Psychological Research
Fallibility of intui tion
H indsight Bias (I knew i t all along.)
Judgmental Overconfidence
I l lusory Correlation
The Scientific Attitude
Cu r iosity, Skepticism, H umility
Cr itical Thinking
Why do people believe strange things?
Research Strategies: How Psychologists Ask and Answer Questions
Module 3
How do Psychologists Ask and Answer Questions?
The Scientific Method
Description
Correlation
Experimentation
The Scientific Method
Theory- predicts behavior or events through an integrated set of principles
Example: low self-esteem contributes to depression.
Must lead to hypothesis
E.g., People with lower self-esteem are more likely to feel depressed.
Predictions that are TESTABLE
e.g., the lower your self-esteem, the more likely you are to be depressed
Replicable
Research
Disprovable
The Research Process
Research Strategies: Description
Case Study- when a psychologist observes one person or small groups;
usually done when whatever you want to figure out is ra re.
Su rvey- way to assess; give people a set of quest ions and have them answer it
Wording effects- way you word something can impact t he answer you get
Random sampling
Posit ive impression management
Nat uralist ic Observat ion
These st rategies DESCRIBE behavior.
Research St rategies: Descript ion
Case St udy
Survey
Wording effects
Random sampling
Positive impression management
Example of Wording Effect
Do you think the U.S. should forbid p ublic speeches against democracy? 54% said
Y ES
Do you think the U.S. should a llow p ublic speeches against democracy 75% said no
Survey
Random sample (unbiased) = if each member has an equal chance of inclusion
i nto a sample from a population.
If the survey sample is biased, the results are questionable.
Naturalistic Observation
These strategies DESCRIBE behavior.
Research Strategies: Description
Case Study
Survey
Wording effects
Random sampling
Positive impression management- environment say what you want to hear; hard to
get a t rue response; people lie
Natu ralistic Observation-observe people in thei r natu ral ; just watching no
t alking
These strategies DESCRIBE behavior.
Research Strategies: Correlation
How two variables change together
Correlation coefficient: r
- 1.0 to + 1.0
Research Strategies: Correlation
How two variables change together
Correlation coefficient: r
- 1.0 to + 1.0
Scatterplots
Positive correlation- when one variable gets higher, the other variable gets
higher (ex. Hotter days, people buy more ice cream)
Negative correlation- as one variable decreases, the other variable decreases
(ex. More alcohol, worse driving)
No relationship- a correlation that doesnt exist
_____________________ 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.
The Scatterplot below shows the relationship between height and
temperament in people
The previous graph demonstrated a
Positive correlation
Negative correlation
No correlation
There is a moderate positive correlation of +0.63.
Which correlat ion coefficient is the st rongest? (the higher the number, t he
st ronger the relat ionship)
+0.05
-0.25
+0.75
-0.95
Correlat ion and Causat ion
CORREL ATION DOES N O T I MPLY CAUSATION!!
Main points:
Correlation is useful for prediction
Correlation does NOT equal causation
Just because two things are related does not mean that one causes the other
The closer to (+/-) 1.0 the stronger the relationship between two variables is
The (+/-) only indicates the direction, not strength, of the relationship
Research Strategies: Experimental
Looking for CAUSE and EFFECT relationships
Manipulate the independent variable and observe i ts effect on the dependent
variable.
Exploring Cause & Effect
Many factors influence our behavior. Experiments manipulate factors that
i nterest us while keeping other factors under control.
Effects generated by manipulated factors isolate cause and effect
r elationships.
Independent vs. Dependent Variables
Independent Variable is a factor, manipulated by the experimenter.
Dependent Variable is a factor that may change in response to manipulations
of the independent variable.
For example, to study the effect of breast feeding on intelligence, breast
feeding is the independent variable.
Int roducing the Experiment
E.g., A word-pleasantness experiment
Hypothesis: Pleasant stimuli are more likely to be recalled than unpleasant
stimuli.
Method: Participants are shown a list of words and asked to rate the
pleasantness of those words. A few minutes later, they are asked to recall as
many of the words as possible.
Results: On average, participants recalled significantly more pleasant words
than unpleasant words.
From the previous example, which of the following is the independent variable?
The number of words that the participants recalled
The type of words that were presented (pleasant versus unpleasant)
The amount of time given to recall the words
Experimental Research Strategy
Hold other factors constant
Random assignment to:
Experimental condition
Control condition
Ex.does cognitive therapy improve depression?
One group assigned to cognitive therapy
One group assigned to spend an equal amount of time with a therapist, but
without cognitive therapy strategies
Reporting Statistics
Correlation
Measures of central tendency:
Mode- The number that occurs the most often in a string of numbers
Mean- the average; add all the numbers up and divide by the number there
are
Median- from lowest to highest line up the numbers, the median is directly in
the middle
Variation:
Range- lowest number to the highest number
Standard deviation- formula; how much the scores vary around a mean
Reporting Statistics Set #1:
73, 75, 76, 78, 78
Mode: 78
Mean: 76
Median: 76
Standard Deviation: 1.52
Set #2:
30, 70, 80, 80, 120
Mode: 80
Mean: 76
Median: 80
Standard Deviation: 32.09