Chapter 14 Eysenck’s Biologically Based Factor Theory 429Concept of Humanity
On the determinism versus free choice dimension, Eysenck’s theory sides some-
what toward the deterministic view, but only slightly. Biological foundations are
difficult to change, but as the diathesis-stress models make clear, both biology
and environment are needed to create final personality qualities in an individual.
Regarding optimism versus pessimism Eysenck is mostly silent, but on
teleology versus causality he comes down on the side of causality. Recall the
model in Fig ure 14.5, where the chain of causality runs from DNA to limbic
system to traits to proximal consequences and finally to distal consequences.
On the question of conscious versus unconscious determinants of
behavior, Eysenck’s approach leans toward unconscious determinants insofar
as people are mostly incapable of being aware of how genetics and brain
processes affect their behavior and personality. Regarding the issue of bio-
logical versus social influences it may be somewhat surprising to say, but in
fact, Eysenck very much argued for “both-and”—both nature and nurture. Biol-
ogy may set the floor and ceiling of our behavior, but environment is needed
to determine whether we will be closer to the floor or ceiling of our potential.
On the dimension of individual differences versus similarities, biologi-
cal theory leans quite a bit toward individual differences. Biological, brain,
and genetic differences focus on the uniqueness of individuals. Eysenck
(1981), for example, wrote that “people are above all individuals” (p. xi). And
yet at the same time, biological theory also demonstrates the commonality
we all share as members of a single species. In that we are all members of
the same species, we expect to see and do see commonality in personality
structure the world over.
Key Terms and Concepts
∙ (^) Eysenck used a hypothetico-deductive approach to extract three bipolar
factors—extraversion/introversion, neuroticism/stability, and
psychoticism/superego.
∙ (^) Extraverts are characterized by sociability and impulsiveness; introverts,
by passivity and thoughtfulness.
∙ (^) High scores on the neuroticism scale may indicate anxiety, hysteria,
obsessive-compulsive disorders, or criminality; low scores tend to predict
emotional stability.
∙ (^) High scores on psychoticism indicate hostility, self-centeredness,
suspicion, nonconformity, and antisocial behavior; low scores indicate a
strong superego, empathy, and cooperation.
∙ (^) Eysenck insisted that, to be useful, personality must predict behavior,
and he presented ample evidence to support his three-factor theory.
∙ (^) The three main dimensions of personality are biologically based as
evidenced from temperament, behavioral genetics, and brain research.