Feist−Feist: Theories of
Personality, Seventh
EditionIV. Dispositional Theories 14. Eysenck, McCrae, and
Costa’s Trait and Factor
Theories© The McGraw−Hill^435
Companies, 2009person may join a dance club, whereas an assertive person may become a lawyer or
business executive.
The second characteristic adaptation postulate—maladjustment—suggests
that our responses are not always consistent with personal goals or cultural values.
For example, when introversion is carried to extreme, it may result in pathological
social shyness, which prevents people from going out of the house or holding down
a job. Also, aggression carried to an extreme may lead to belligerence and antago-
nism, which then result in being frequently fired from jobs. These habits, attitudes,
and competencies that make up characteristic adaptations sometimes become so
rigid or compulsive that they become maladaptive.
The third characteristic adaptation postulate states that basic traits may
“change over time in response to biological maturation, changes in the environment,
or deliberate interventions” (McCrae & Costa, 2003, p. 190). This is McCrae and
Costa’s plasticity postulate, one that recognizes that although basic tendencies may
be rather stable over the lifetime, characteristic adaptations are not. For example, in-
terventions such as psychotherapy and behavior modification may have a difficult
time changing a person’s fundamental traits, but they may be potent enough to alter
a person’s characteristic responses.
Related Research
The trait approach taken by Hans Eysenck, Robert McCrae, and Paul Costa is very
popular in the field of personality. Eysenck and Costa and McCrae have developed
widely used personality inventories, namely the Eysenck Personality Inventory and
its offshoots (Eysenck, 1959; Eysenck & Eysenck, 1964, 1968, 1975, 1993) and the
NEO-PI (Costa & McCrae, 1985, 1992).
Traits have been linked to vital outcomes such as physical health (Martin,
Friedman, & Schwartz, 2007), well-being (Costa & McCrae, 1980), and academic
success (Noftle & Robins, 2007; Zyphur, Islam, & Landis, 2007); but traits have also
been linked to more common, everyday outcomes such as mood (McNiel & Fleeson,
2006). As seen below, traits can predict long-term outcomes like GPA (Noftle &
Robins, 2007) that are the product of years of work, but traits can also predict more
discrete outcomes like how many times you will take a college entrance exam such
as the SAT (Zyphur, Islam, & Landis, 2007) and what kind of mood you might be in
on any given day (McNiel & Fleeson, 2006).
The Biology of Personality Traits
One of the major thrusts of Eysenck’s theory is that personality dimensions are not ar-
bitrary creations of culture but, rather, result from the basic genetic and neurophysi-
ological makeup of the human species. If there were a biological basis to personality,
two key assumptions should hold true. First, neurophysiological differences should
exist between people high on one end of a dimension (for instance, introversion) and
those high on the other end of that dimension (for instance, extraverts). Second, the
basic personality dimensions should be universal and not limited to a given culture.
The first domain to test Eysenck’s biological model of personality is in neuro-
physiology. If, as Eysenck proposed, introverts have lower thresholds of arousal than
Chapter 14 Eysenck, McCrae, and Costa’s Trait and Factor Theories 429