Carnegie Mellon University


For additional measures of extraversion see Big Five Personality Factors


Eysenck Personality Inventory (EPI) – Extraversion scale



Primary Reference

Eysenck, H. J., Eysenck, S. B. G. (1964).  Manual of the Eysenck Personality Inventory. London, England: University of London Press.


To evaluate extraversion and its subcomponents of sociability and impulsivity as stable measures of personality

Type of Measure

Modified.  The scale administered in BCS included all 24 of the items comprising the original EPI extraversion scale, as well as an additional item that originally was scored as part of the EPI neuroticism scale (feel shy when wanting to talk to an attractive stranger).


Participants respond to a series of questions regarding how they might behave in various social situations; their attitudes toward different types of social activities; and their tendencies toward impulsivity in general.  All items are presented using a dichotomous yes/no response format.


1=yes, 0=no

Number of Items


Sample Items

  • Do you like going out a lot?
  • Do you generally do or say things without stopping to think?
  • Are you mostly quiet when you are with other people? (reversed)


Internal consistencies in BCS (n = 342):

  • Extraversion, Cronbach’s α = 0.81
  • Impulsivity, Cronbach’s α = 0.57
  • Sociability, Cronbach’s α = 0.79


Extraversion total score – sum of all items (14 directly scored, 11 reverse-scored)

Impulsivity subscore – sum of 9 items (6 directly scored, 3 reverse-scored)

Sociability subscore – sum of 13 items (6 directly scored, 7 reverse-scored)