574 CHAPTER 13
Understanding Personality Disorders in General
At one point, Reiland became impatient with her 4-year-old son Jeffrey and “lost
it.” She slapped, then cursed him. As he cried, she commanded him to stop crying.
He didn’t, and she proceeded to spank him so hard that it hurt her hand.
He had stopped crying, his fright overcoming his need to express his emotions. But his
eyes were wide open, as big as I’d ever seen them. And absolutely, unequivocally horri-
fi ed. That look stopped me.
The familiar feeling of weightlessness overtook me again. I knew Jeffrey’s look.
I knew that feeling.
It had been a common part of my childhood—enduring rages that began and ended
just as unpredictably. The reality slowly sunk in. I had beaten my child. Just as my fa-
ther had beaten his. Just as I swore I never ever would. A wave of nausea rose within
me. I was just like my father. Even my children would be better off without me. There
was no longer any reason to stay alive.
(Reiland, 2004, p. 19)
Reiland’s realization was relatively unusual for someone with a personality dis-
order: She recognized in this instance that it was she who created a problem—she
who had done something wrong, although her father never recognized his respon-
sibility. He too was quick to anger and hit her and her siblings. Do personality
disorders run in families? If so, to what extent do genes and environment lead to
personality disorders? How might personality disorders arise?Neurological Factors in Personality Disorders:
Genes and Temperament
Perhaps the most infl uential neurological factor associated with personality disorders
is genes (Cloninger, 2005; Paris, 2005). Researchers have not produced evidence that
genes underlie specifi c personality disorders, but they have shown that genes clearly
infl uence temperament, which is the aspect of personality that refl ects a person’s typ-
ical affective state and emotional reactivity (see Chapter 2). Temperament, in turn,
plays a major role in personality disorders. Genes infl uence temperament via their
effects on brain structure and function, including neurotransmitter activity.
It is possible that the genes that affect personality traits can predispose some
people to develop a personality disorder. For instance, some people are genetically
predisposed to seek out novel and exciting stimuli, such as those associated with
stock trading, race car driving, or bungee jumping, whereas other people are predis-
posed to become easily overstimulated and habitually prefer low-key, quiet activities,
such as reading, writing, or walking in the woods. Such differences in temperament
are the foundation on which different personality traits are built—and, at their
extremes, temperaments can give rise to infl exible personality traits that are associ-
ated with personality disorders. Examples include a novelty seeker (temperament)
who compulsively seeks out ever more exciting activities (infl exible behavior pat-
tern), regardless of the consequences, and a person who avoids overstimulation (tem-
perament) and turns down promotions because the new position would require too
many activities that would be overstimulating (infl exible behavior pattern).
Reiland may well have inherited a tendency to develop certain aspects of temper-
ament, which increased the likelihood of her behaving like her father in certain types
of situations. However, her genes and her temperament don’t paint the whole picture;
psychological and social factors also infl uenced how she thought, felt, and behaved.Psychological Factors in Personality Disorders:
Temperament and the Consequences of Behavior
Two psychological factors signifi cantly contribute to personality disorders: tempera-
ment and operant conditioning. Although infl uenced by genes, temperament is also
shaped by the environment—and ultimately is best conceptualized as a psychologi-
cal factor. As just noted, temperament infl uences the types of situations to which
individuals are likely to gravitate and to avoid—and how they are likely to behaveP SN