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Introduction to Psychology
Psychology: The scientific study of mental processes and behavior.
What do we mean by “mental processes” and “behavior”?
What is the scope of psychology?
What are some advantages to such a diverse area of study?
What are some limitations?
All psychologists have two general goals:
1. Understand mental processes and behavior
2. Apply that understanding in the service of human welfare
What do we mean by “understand” and “apply”?
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Major Philosophical & Theoretical
Foundations of Psychology
Very Early Philosophical Foundations
1. Empiricism (17th century)
Major Proponents: Locke, Hume
Knowledge comes through observation and experience.
2. Structuralism (19th century)
Major Proponents: Wundt, Titchner
Endeavors to study the components of the mind, as well as the
relationships among those components ("quality" and "intensity").
3. Gestaltism (19th – 20th century)
Major Proponents: Wertherimer, Koffka, Kohler
Mental experiences are only meaningful when interpreted as a
whole. The whole is more meaningful than the sum of its parts.
4. Functionalism (late 19th – 20th century)
Major Proponents: James, McDougall
Assumes that the mind and behavior have adaptive purposes.
Endeavors to study what the mind and behavior are for.
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Contemporary Theoretical Perspectives
1. Behaviorism
(Watson, Pavlov, Skinner)
Watson (1913) insists that for psychology to become a true natural
science, it must be restricted to studying observable behaviors.
2. Psychoanalytic (Freud, Jung, Adler)
Examines the influences of unconscious processes on personality,
behavior, and mental illness.
3. Humanistic (Rogers, Maslow)
Focuses on an individual’s potential for personal growth.
4. Biological (Loewi, Sherrington, Olds, Sperry)
With the discovery of neurons and neurotransmission, a deeper
understanding of the brain and nervous system develops.
5. Sociobiological/Evolutionary (Wilson, Buss, Dawkins)
Interprets mental processes and behavior in terms of their adaptive
value to the survival of a species.
6. Cognitive (Atkinson, Schiffrin, Broadbent, Miller,
Anderson, Neisser)
With the advent of the computer, psychologists were provided with
a new metaphor for how humans processed, stored, and retrieved
information.
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How Do Psychologists Acquire Knowledge
About Mental Processes & Behavior?
Psychologists alone are not the only individuals who study mental
processes and behavior ...
What are some other disciplines that endeavor to understand
mental processes and behavior?
Empirical Research: the systematic gathering and analysis of
information.
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Conducting Empirical Research
Empirical Research: the systematic gathering and analysis of
information.
Preliminary Steps in The Empirical Research Process
1.
Identify a Problem: the research question
2.
Review the relevant literature
3.
Theoretical Considerations: what is the theory? Is there
one?
Theory: a system of interrelated ideas used to explain a set of
observations that comprise a complex phenomenon of interest.
A good theory:
(a) provides a logical explanation of the phenomenon
(b) is falsifiable through scientific investigation
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Major Steps in Scientific Investigation
1.
Develop a hypothesis
Hypothesis: a testable prediction about the relationship
between the relevant variables.
To test a research hypothesis:
a.
Select a phenomenon of interest, and identify relevant
variables
b.
Control and measure relevant variables and minimize
influence of irrelevant variables
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Identifying Relevant Variables
Hypothetical Constructs &
Observable Variables
Hypothetical Constructs:
Ideas or concepts that describe a psychological phenomenon. They
are theoretical definitions!
What might be some examples?
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How do you study hypothetical constructs?
Hypothetical constructs must be operationally defined into
observable variables.
Operational Definition:
The operations (behaviors/manipulations), events, or stimulus
conditions that relate to the hypothetical construct.
Operationally defined variables be observed and objectively
measured or controlled.
They establish precisely what is meant by each variable in the
study.
Based on the observable variables specified by the operational
definition, you can now develop a testable hypothesis about the
phenomenon of interest.
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Independent Variables, Dependent Variables, and Extraneous
Variables
Independent Variable:
A variable that is causal, explanatory, or predictive. Usually (but
not always) manipulated.
(“True” vs. “Participant” IV’s)
Dependent Variable:
A measured or observed variable.
Predicted, influenced, or explained by the IV.
Extraneous Variables (Irrelevant variables):
Factors other than the independent variable that can influence the
dependent variable.
(Nuisance variables and Confounds)
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2.
Select an appropriate method of researching the problem
and design the study
There are two major types of research:
1.
Descriptive/Correlational:
Focuses on carefully mapping out a situation, and examining
how two or more events change together over time.
General correlational hypothesis:
Changes in X are related to changes in Y
2.
Experimental:
Focuses on the identification of cause and effect by
manipulating one variable to examine its effect on another
variable.
General experimental hypothesis:
Changes in X are responsible for changes in Y
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Types of Descriptive/Correlational Research
Case Studies: a detailed examination of a particular behavior,
mental process, disorder, etc. found in a single individual.
Example: interviewing someone with brain damage.
Advantages:
May be the only way to study a rare or complex
phenomenon...
Disadvantages:
Difficult to draw conclusions based on only a single case
Highly subjective
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Types of Descriptive/Correlational Research
Naturalistic Observation: observes people or animals in natural
environment.
Example: observing people in a queue
Advantages:
Best way to examine a phenomenon!
Disadvantages:
Observer Bias
Lack of Control
Observer Interference
People behave differently when watched
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Types of Descriptive/Correlational Research
Measurement Research: measurements of attributes, skills,
abilities, or task performance are measured with as much precision
as possible. Relations between scores are examined.
Example: measuring SAT’s and also college GPA to examine the
relationship.
Advantages:
Allows for prediction, best option when no control
Disadvantages:
Measurement error
Lack of control
The “Third variable” problem
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Types of Descriptive/Correlational Research
Survey Research: ask self-report questions to a large number of
people. Examine relationships between attitudes and behavior.
Example: Do attitudes about job satisfaction relate to job
performance?
Advantages:
Easy
Cheap
Fast way to obtain a lot of information!
Disadvantages:
All of the disadvantages of measurement research plus:
Questions may be poorly constructed
People may lie about responses or not be able to answer
accurately
Opinions may not relate to actual events in real world
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Types of Experimental Research
True Experiments: manipulate an independent variable (IV) to see
how it influences a dependent (measured) variable (DV).
Differences are compared between a group that was randomly
assigned to receive one level of the IV and one or more groups that
were randomly assigned to receive a different level of the IV or a
placebo.
Example: comparing recall between three groups or participants,
500 mg Super Ginkgo, 250 mg Super Ginkgo, and placebo.
Advantages:
Can establish a cause and effect relationship between variables
Greatest amount of precision and control
Disadvantages:
May be artificial (external validity)
Practical and ethical concerns
Still can never rule out chance
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Types of Experimental/Causal Research
Quasi-Experiment: when it is neither possible nor ethical to
randomly group people by manipulation of variables.
Example: Comparing visual memory between females and males.
Advantages:
Still enables you to (more or less) examine cause and effect
Disadvantages:
Can't control random assignment so it's harder to draw
conclusions.
It’s really a correlational design.
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Some Examples of IV’s, DV’s, and Extraneous Variables
Type of
Research
Causal:
True Exp.
IV
DV
possible
Extr. Var
lever pressing room
for water
temperature
Hours of
water
deprivation
Causal:
Number of
play time
prior
True Exp.
hidden
boredom
switches a toy
Causal:
Dose of
motor activity tolerance to
True Exp.
caffeine
caffeine
Causal:
Sex (F or M) Accuracy of previous
Quasi Exp.
depth
experience
perception
with task
Relational:
SAT scores
college GPA study or test
measurement
anxiety
Relational:
IQ score
yearly income SES
measurement
Relational:
scores on the time spent
like or
survey
(self report)
observing a
dislike for
Perceptual
novel
the subject
Curiosity
photograph
matter of the
scale
photograph
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3.
Recruit participants, conduct study, collect data
Samples and Populations
Representativeness & sampling Bias
Random sampling vs. random assignment
4.
Conduct statistical analyses that will facilitate description
and interpretation of your data in order to draw
conclusions
Descriptive Statistics: summarize the data
I.
Central Tendency: a "typical" score or value
Mean: average score
(total/n)
Mode: most frequently occurring score
Median: the middle score (1/2 above and 1/2 below)
II. Variability: how much the scores differ from one another; the
spread in a data set.
Range: the range in scores (highest - lowest)
Standard Deviation: standardized average variance of
each score from the mean
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III. Relational Statistics: indicates how two or more variables are
related to one another.
Correlation coefficient: the direction and magnitude of
covariation between two variables (ranges from 1.0 to -1.0).
We assume that values for X and Y are random.
Regression: tells you how well a variable (x) can predict
changes in another variable or variables (Y). We assume that
values for X are fixed and that values for Y are random.
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IV. Inferential Tests
t-test: used to compare two group means to see if they are
"significantly*" different from one another.
ANOVA: used to compare more than two group means.
*a "significant" difference between group means is interpreted that
the difference is not likely to be due to chance.
5.
Report your findings, and share with the scientific
community!