Chapter 14 Eysenck’s Biologically Based Factor Theory 409C
hance and fortuity often play a decisive role in people’s lives. One such
chance event happened to an 18-year-old German youth who had left his
native country as a consequence of Nazi tyranny. He eventually settled in
England, where he tried to enroll in the University of London. He was an avid
reader, interested in both the arts and the sciences, but his first choice of
curriculum was physics.
However, a chance event altered the flow of his life and consequently the
course of the history of psychology. In order to be accepted into the university, he
was required to pass an entrance examination, which he took after a year’s study
at a commercial college. After passing the exam, he confidently enrolled in the
University of London, intending to major in physics. However, he was told that
he had taken the wrong subjects in his entrance exam and therefore was not eli-
gible to pursue a physics curriculum. Rather than waiting another year to take the
right subjects, he asked if there was some scientific subject that he was qualified
to pursue. When told he could always take psychology, he asked, “What on earth
is psychology?” He had never heard of psychology, although he had some vague
idea about psychoanalysis. Could psychology possibly be a science? However, he
had little choice but to pursue a degree in psychology, so he promptly entered the
university with a major in a discipline about which he knew almost nothing. Years
later the world of psychology would know a great deal about Hans J. Eysenck,
probably the most prolific writer in the history of psychology. In his autobiography,
Eysenck (1997b) simply noted that by such chance events “is one’s fate decided
by bureaucratic stupidity” (p. 47).
Throughout his life, Eysenck battled bureaucratic stupidity and any other type
of stupidity he came across. In his autobiography, he described himself as “a
sanctimonious prig... who didn’t suffer fools (or even ordinarily bright people)
gladly” (Eysenck, 1997b, p. 31).Overview of Biologically Based
Trait Theory
Every theory of personality discussed so far has downplayed, ignored, or even
argued against the biological basis of human personality. Only McCrae and
Costa (see Chapter 13) placed even mild emphasis on genetic and biological
influences on personality.
With Eysenck that changed. Eysenck developed a factor theory much like
McCrae and Costa, but because he fundamentally based his taxonomy in both
factor analysis and biology, he derived only three, rather than five, dimensions
of personality—extraversion/introversion, neuroticism/stability, and psychoticism/
superego. We’ll discuss these more later in the chapter, but the key for Eysenck
was that the individual differences in people’s personalities were biological,
and not merely psychological, aspects of personality. That is, genetic differences
lead to structural differences in the central nervous system, including brain struc-
tures, hormones, and neurotransmitters, and these differences in biology lead to
differences along the three factors of personality—extraversion, neuroticism, and
psychoticism.