Feist−Feist: Theories of
Personality, Seventh
EditionIV. Dispositional Theories 14. Eysenck, McCrae, and
Costa’s Trait and Factor
Theories© The McGraw−Hill^421
Companies, 2009dimensional space cannot be faithfully produced on a two-dimensional plane, the
reader is asked to look at Figure 14.6 as if the solid lines represent the corner of a
room where two walls meet the floor. Each line can then be seen as perpendicular to
the other two.) Eysenck’s view of personality, therefore, allows each person to be
measured on three independent factors and resultant scores to be plotted in space
having three coordinates. Person F in Figure 14.6, for example, is quite high on
superego, somewhat high on extraversion, and near the midpoint on the neuroti-
cism/stability scale. In similar fashion, scores of each person can be plotted in three-
dimensional space.
Measuring Personality
Eysenck evolved four personality inventories that measure his superfactors. The first,
the Maudsley Personality Inventory, or MPI (Eysenck, 1959), assessed only E and N
and yielded some correlation between these two factors. For this reason, Eysenck de-
veloped another test, the Eysenck Personality Inventory, or EPI. The EPI contains a
lie (L) scale to detect faking, but more importantly, it measures extraversion and neu-
roticism independently, with a near zero correlation between E and N (H. J. Eysenck
& B. G. Eysenck, 1964, 1968). The Eysenck Personality Inventory was extended to
children 7 to 16 years of age by Sybil B. G. Eysenck (1965), who developed the Ju-
nior EPI.
The EPI was still a two-factor inventory, so consequently Hans Eysenck and
Sybil Eysenck (1975) published a third personality test, namely the Eysenck Per-
sonality Questionnaire (EPQ), which included a psychoticism (P) scale. The EPQ,
which has both an adult and a junior version, is a revision of the still-published EPI.
Subsequent criticisms of the P scale led to yet another revision, the Eysenck Per-
sonality Questionnaire-Revised (H. J. Eysenck & S. B. G. Eysenck, 1993).
Biological Bases of Personality
According to Eysenck, personality factors P, E, and N all have powerful biological
determinants. He estimated that about three fourths of the variance of all three per-
sonality dimensions can be accounted for by heredity and about one fourth by envi-
ronmental factors.
Eysenck (1990) cited three threads of evidence for a strong biological com-
ponent in personality. First, researchers (McCrae & Allik, 2002) have found nearly
identical factors among people in various parts of the world, not only in Western Eu-
rope and North America but also in Uganda, Nigeria, Japan, China, Russia, and other
African and European countries. Second, evidence (McCrae & Costa, 2003) sug-
gests that individuals tend to maintain their position over time on the different di-
mensions of personality. And third, studies of twins (Eysenck, 1990) show a higher
concordance between identical twins than between same-gender fraternal twins
reared together, suggesting that genetic factors play a dominant part in determining
individual differences in personality.
In Eysenck’s theory of personality, psychoticism, extraversion, and neuroti-
cism have both antecedents and consequences. The antecedents are genetic and
Chapter 14 Eysenck, McCrae, and Costa’s Trait and Factor Theories 415