Personality
•	What personality is
•	Trait models
•	Measurement issues
•	Biology of personality
•	Cognitive theories
•	Personality style
•	Mischel’s critique
What is Personality?
•	A set of characteristics
•	Consistent across time
•	Consistent across situations
•	Distinguishes individuals from each other
Important Questions
•	Study of individuals or individual differences?
•	Are traits descriptive or dispositional?
•	Structure
•	Hierarchy
•	Centrality
Trait Theories
•	How many traits do we need?
•	Different numbers of factors
•	Nearly all have extraversion and neuroticism
•	Useful for conceptualizing personality
The Big Five:
Superfactors of Personality
Measuring Personality: Observation
•	Problems of reliability and consistency
•	Behavior can mean many things
•	Still has to be coded into trait categories
Measuring Personality: Interviews
•	Works best if highly structured
•	But then why use an interview?

Measuring Personality:
Inventories
•	Questionnaires (paper or computer)
•	Produce a personality profile
•	Easy to score and statistically analyze
•	Generally no hidden agendas
Measuring Personality: Projective Tests
•	Include Rorschach and TAT
•	Concerns about validity and reliability
The Brain and Personality
•	Certain biological tendencies may affect personality
•	Extraverts are less arousable than introverts
•	Neuroticism may be related to the sensitivity of emotional parts of the brain
•	Underarousal of nervous system may be related to risk taking or criminal behavior
Temperament
•	Innate tendencies to behave in certain ways
•	Correlation between temperament at infancy and adulthood
•	An example: sensation seeking
•	Tendency to engage in risky behavior
•	Related to levels of blood chemicals
A Genetic Link
•	Minnesota Twin Studies
•	Identical and fraternal twins
•	Raised together or apart
•	Calculate heritability of personality traits
•	Significant effect of heritability on traits
Cognitive Theories
•	George Kelly’s Personal Construct Theory
•	How people construe situations is crucial
•	Rep test
Personality Styles (1950-1970)
•	Begins with Authoritarian Personality
•	Syndrome of traits and features
•	Held together by common higher order motives
•	Concerns with California F-Scale in terms of acquiescence  bias 
•	Later styles
•	Internal-external
•	Complexity
•	Social desirability and social approval
The Mischel Critique
•	Walter Mischel 1977
•	Behavior is not consistent across situations
•	Typically low correlations
•	And trait measures do not predict behavior very well
•	Situations control behavior – part of a much larger critique
Subsequent Mischel
•	People do have fairly consistent goals
•	And fashion behavior to meet them
•	Have a clear sense of what behaviors will work in what situations
•	How situations are construed --- Kelly
•	The “if…then…” model
•	Therefore have to understand cognition and planning
Mischel’s Version of Consistency
•	Interrelations of affects, goals, plan, etc.
•	Profiles of behavior across situations
Responses to Mischel
•	Predicting behavior is better when aggregate across situations -- Epstein
•	Religion example
•	Often want to predict single behavior
•	Person-situation interaction works better but also not practical
What’s wrong with the Mischel approach?
•	Philosophical dead-end
•	If microscopic enough can always predict better
•	But how microscopic
•	“if..then” model is not very practical
•	Still need to predict behavior of people grossly
•	And map people onto the same dimensions
•	Individuality is nice, but…