Personality traits

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Personality traits Powered By Docstoc
Trait models of personality
Following this lecture/reading you should be
  able to:–
 Demonstrate an understanding of how
  personality traits may be identified
 Describe & critically evaluate the trait
  theories of Cattell, Eysenck and Costa &
 Address the criticism of circularity
 IndividualDifferences Ch. 5
 Some of the recommended reading: e.g.,
  Block (1995), or Eysenck (1992) & Costa &
  McCrae (1992)
 Plenty of words describe enduring
  dispositions. e.g., happy, demanding, mean,
  aggressive, neurotic, anxious… Aristotle
 Key assumptions:
  –   stability of behaviour over time
  –   stability of behaviour across situations
  –   traits are “inside us”
  –   they influence our behaviour
               traits & states
 Traits: enduring ways of behaving
 States: moods/emotions. Vary
  – over time
  – as a function of situation & life events
 So  a trait should correspond to an „average
Why not just use adjectives from
 the dictionary to define traits?
 …too  many to use! (~18 000 words)
 …need hard evidence that each describes
  consistent behaviours
 …& impossible to tell whether some words
  mean the same as others.
            What is needed
A   method of discovering the main
  personality traits
 …which should show up through
  behavioural ratings, questionnaires, &
  perhaps objective tests
 …be stable over time
 …and predict performance in a variety of
            Factor analysis
 Used  to analyse responses from behavioural
  rating-scales and/or questionnaires.
 Looks for items that tend to vary together
  from person to person.
           Responses to 6 items
             Susan      Bob          Mary   Ian

Insurance    Hurts   Suspicion   Optimist   Enjoys    Talkative
  useless loved ones                        parties
             Factor analysis
 shows  how many groups of items (TRAITS)
  there are, and
 which items belong to which group(s).

It is claimed that factor analysis can reveal
   causal influences (“source traits”). e.g.,
   factoring behaviours related to drinking…
    Guilford & Guilford (1934)
 Factored  responses to 36 items Why
  THESE 36?
 Didn‟t find the one („extraversion‟) factor
  they‟d expected
 …but 4 factors: introversion, emotionality,
  impulsivity, self-interest
 …and by 1956 had found 9 more
                Cattell (1943)
 Personality  Sphere. Tried to measure all
  possible trait-descriptors.
  –   4500 adjectives (Allport & Odbert, 1938)
  –   Removing synonyms reduced this to 171
  –   Claimed to measure these 171 variables
  –   Factor analysed & found about 46 factors
  –   Some of which are measured by the 16PF
  –   But his work can‟t be replicated.
             Cattell‟s factors
A   Warm/reserved           L    Suspicious/trusting
B   [Intelligent]           M    Imaginative/practical
C   Unemotional/emotional N      Shrewd/Forthright
E   Assertive/co-operative O     Guilty/self-assured
F   Cheerful/sober          Q1   Radical/conservative
G   Conscientious/expedient Q2   Self sufficient/affiliative
H   Socially bold/shy       Q3   Controlled/impulsive
I   Self-reliant/sensitive Q4    Tense/tranquil
             Hans Eysenck
 Wanted  to identify neurotics
 But found 2 factors (extraversion &
 Later added „psychoticism‟ (1976)
 Eysenck‟s 3 factors are easy to replicate
         Extraverts. Del boy
 are sociable
 take risks
 don‟t persevere
 are unreliable
 can lose their temper
 are assertive
 are carefree
           Neurotics: Piglet
 Feel anxious
 Feel depressed
 Feel guilty
 Feel tense
 Feel moody
 Get emotional
   Psychotics: Francis Urquart
 Aggressive
 Cold  & impersonal
 Self-centred
 Impulsive
 Lacking empathy
 Creative
 Tough-minded
Norman (1962)/Costa & McCrae
 Five factor model: Extraversion,
  Neuroticism, Openness to experience,
  Agreeableness, Conscientiousness.
  (Acronym: OCEAN)
 Based on (flawed?) ratings of behaviour
 Some notable problems in replicating the
  factor structure
 P=low agreeableness/conscientiousness?
 Why such different results from
       various studies?
 Different ways of sampling/selecting items
  for ratings or self-report
 Quality of data varies – e.g., Tupes &
  Christal (1961)
 Quality of factor analysis
 Insufficient interest in properly validating
  factors before publishing a model.
Beware of doing the following:-
  – Observing behaviour (e.g., Claire is
    apprehensive, easily upset, keeps her room
    compulsively tidy)
  – Inferring that Claire is high on a trait of
  – Saying that this high score „explains‟ her
    apprehension etc.
To EXPLAIN behaviour using traits, it is necessary
   to show that what‟s measured by the questionnaire
   reflects some more fundamental process
c/f an acid turns litmus red. x turns litmus red. Thus
   x is an acid. The concept of „acidity‟ is only
   useful if acids have broader properties than
   turning litmus red. Which they do...
So what are the broader implications of personality
 see   next lecture! (after break)
             To conclude:–
 Factor  analysis has been useful in
  discovering the main traits
 There is universal agreement for 2 main
  traits (extraversion, neuroticism)
 Opinions differ about the rest!
 Circularity is an important issue, so
 Check traits are broader in scope than the
  methods used to measure them.