Personality traits

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					         PSY224
Trait models of personality
               Objectives
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 &
  McCrae
 Address the criticism of circularity
                Reading
 IndividualDifferences Ch. 5
 Some of the recommended reading: e.g.,
  Block (1995), or Eysenck (1992) & Costa &
  McCrae (1992)
                       Traits
 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
  state‟
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
  situations.
            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

  7
  6
  5
  4
  3
   2
   1
   0
Insurance    Hurts   Suspicion   Optimist   Enjoys    Talkative
  useless loved ones                        parties
                              Item
             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 &
  neuroticism)
 Later added „psychoticism‟ (1976)
 MMQ, MPI, EPI, EPQ, EPQR
  questionnaires.
 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.
                 Circularity
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
    Neuroticism
  – Saying that this high score „explains‟ her
    apprehension etc.
                      …ctd
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
   traits?
 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.

				
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