psychology 3051 psychology 305: theories of personality lecture 1
DESCRIPTION
Psychology 3053 A formal definition: “Personality is a dynamic organization, inside the person, of psychophysical systems that create the person’s characteristic patterns of behaviour, thoughts, and feelings.” -- Carver & Scheier, p. 5 Noteworthy points about this definition: 1.“Psychophysical” 2. “Dynamic” 3.“Organization” 4. “Create” 5.“Characteristic patterns” What is Personality?TRANSCRIPT
Psychology 305 1
Psychology 305: Theories of Personality
Lecture 1
Psychology 305 2
Lecture 1
1. What is personality?
2. What is personality psychology?
3. Why study personality?
4. What is a theory?
5. How is research used to test theories?
Questions That Will be Answered in Today’s Lecture
Psychology 305 3
• A formal definition: “Personality is a dynamic organization, inside the person, of psychophysical systems that create the person’s characteristic patterns of behaviour, thoughts, and feelings.”-- Carver & Scheier, p. 5
• Noteworthy points about this definition:
1. “Psychophysical”
2. “Dynamic”
3. “Organization”
4. “Create”
5. “Characteristic patterns”
What is Personality?
Psychology 305 4
What is Personality Psychology?
• “Every human being is like every other human being, like some other human beings, and like no other human being.”-- Kluckhohn & Murray, 1953
• This quote reflects the three levels of analysis in personality psychology:
1. Human universals (e.g., desire to belong)
2. Group differences (e.g., sex differences)
3. Individual differences
Psychology 305 5
Why Study Personality?
• The study of personality serves three functions:
1. Descriptive function
2. Explanatory function
3. Predictive function
• Predictive function is particularly important in applied settings.
Examples: Clinical settings, military settings, corporate settings.
Psychology 305 6
What is a Theory?
• Theory: A proposed explanation or interpretation of the relations among conceptual variables or constructs.
• Construct: A conceptual or hypothetical variable that can’t be directly observed.
Examples of variables that are constructs: Intelligence, self-esteem, depression, aggression.
Examples of variables that are not constructs: Hair colour, eye colour, weight, height, blood pressure.
Psychology 305 7
• Theories serve two functions.
1. Synthesizing function: Theories should explain and organize
observations that have already been made.
2. Heuristic function: Theories should generate predictions or
hypotheses about phenomena that have not yet been observed.
Psychology 305 8
• A theory is not:
1. a philosophy—a philosophy is broader than a theory.
2. a hypothesis—a hypothesis is more specific than a theory; a theory should generate hypotheses.
3. a taxonomy—a taxonomy is a classification system and does not generate hypotheses.
Psychology 305 9
How is Research Used to Test Theories?
• Operationalization: The translation of a conceptual variable or construct into a variable that can be observed and measured.
• In order to test a theory, researchers must identify observable variables that reflect the conceptual variables or constructs of interest.
Psychology 305 10
• Examples of operationalizations:
Construct: Physical healthOperationalization: Heart rate, blood pressure, cholesterol levels
Construct: AggressionOperationalization: Frequency and intensity of shocks given to a confederate
Construct: IntelligenceOperationalization: Scores on an IQ test
Psychology 305 11
Theories
Hypotheses
Operationalizations
Research
Observations
InteractiveRelationship
Psychology 305 12
• Research Methods
1. Experimental Studies
Designed to examine cause and effect relationships between variables.
Range from simple to complex.
In simple experiments, there are only two levels of the hypothesized “causal” variable or
independent variable (IV).
Psychology 305 13
There are 4 steps involved in a simple experiment:
(a) Participants are pretested on the hypothesized “effect” variable or dependent variable (DV).
(b) Participants are randomly assigned to one of two groups.
(c) The two groups receive different treatments.
(d) The two groups are retested or posttested on the DV.
Psychology 305 14
Pretest
Group A
Group B
Random Assignment
Treatment A
Posttest
A Simple Experiment
Treatment B
Posttest
Psychology 305 15
Step (a) is often omitted.
Advantage of conducting a pretest: Allows the researcher to ensure that random assignment was effective.
Disadvantage of conducting a pretest: Pretest sensitization.
Psychology 305 16
Steps (b) and (c) are necessary to establish causality. That is, participants must be randomly assigned to groups and there must be at least two levels of the IV included in the experiment. Random assignment of participants to multiple levels of an IV is referred to as manipulation of
the IV.
Psychology 305 17
2. Correlational Studies
Designed to examine the extent to which 2 variables covary.
The variables are not manipulated; instead, the naturally-occurring relationship between the variables is examined.
Psychology 305 18
Correlations are typically measured by the Pearson product-moment correlation coefficient (r).
r measures the extent to which a linear relationship exists between 2 variables.
Psychology 305 19
Height
Weight
r = +1.00Positive Linear Relationship
Psychology 305 20
Criminal Activity
Education Level
Negative Linear Relationship
r = -1.00
Psychology 305 21
Exam Performance
Anxiety
Nonlinear or Curvilinear Relationship
r = 0.00
Psychology 305 22
An r = 0.00 would occur between two variables under the following conditions:
(a) The relationship between the variables iscurvilinear.
(b) The variables are completely unrelated (e.g., intelligence and snow boarding ability)
(c) The range of scores used for one or both variables was restricted.
Psychology 305 23
Height
Weight
The Impact of Restricted Range on r
Insufficient variability to allow for a correlation to emerge
Psychology 305 24
Thus, the r between two variables may range in value from +1.00 to -1.00.
• Magnitude of r: strength of the relationship between the variables.
• Sign of r (+ vs. -): direction of the relationship between the variables.
Psychology 305 25
In contrast to experiments, correlational studies do not allow researchers to determine causality.
A correlation between variables A and B may occur because:
A causes B
B causes A
A third unmeasured variable accounts for the observed relationship between A and B—this is referred to as the third variable problem.
Psychology 305 26
Example of the third variable problem:
Self-Esteem Academic Performance
ObservedRelationship, r = .30
??
Intelligence,Socioeconomic Status
TrueRelationship
TrueRelationship
Psychology 305 27
Remedies for the third variable problem:
(a) statistically control for the third variable (i.e., statistically hold the third variable constant for all participants).
(b) experimentally control for the third variable (i.e., recruit participants whose scores on the third variable are identical).
Psychology 305 28
Correlational studies allow the researcher to use the full range of scores on the variable of interest. Therefore, they do not result in loss of information due categorization of participants into experimental groups.
Psychology 305 29
Subject Depression GroupNumber Score
6 3 Low9 28 Low1 30 Low
10 49 Low4 50 Low
---------------------------- Median Split --------------------------2 51 High5 53 High8 67 High3 75 High7 88 High
Example of loss of information associated with categorization:
Psychology 305 30
4. Case Studies
Involve the in-depth examination of the life of one person.
Assessment techniques include: ObservationInterviews Administration of standard personality testsAnalysis of written text
Psychology 305 31
Ted Bundy, 1946 - 1989
Psychology 305 32
Exercise: Application of Research Methods
Construct: Happiness.
Possible operationalizations:
• Measure of life satisfaction.
• Measure assessing the frequency and intensity with which participants experience positive emotions (e.g., joy, contentment, excitement).
• Number of times participants smile.
Psychology 305 33
People experience happiness when they have successfully influenced others’ opinions.
Experimental study.
Hypothesis Ideal Research Method
Psychology 305 34
Group A
Group B
Random Assignment
Treatment A
Posttest
A Simple Experiment
Treatment B
Posttest
Pretest
Psychology 305 35
People experience happiness when they have successfully influenced others’ opinions.
People who report extraordinarily high levels of happiness exhibit a unique constellation of personality characteristics.
People who experience high levels of happiness tend to be more optimistic.
Experimental study.
Case study.
Correlational study.
Hypothesis Ideal Research Method
Psychology 305 36
1. What is personality?
2. What is personality psychology?
3. Why study personality?
4. What is a theory?
5. How is research used to test theories?
Questions That Were Answered in Today’s Lecture