University of Delaware
Office of Public Relations
News Release

      UD prof's study ranks among world's most notable
                              
     University of Delaware Prof. Marvin Zuckerman's
landmark 1971 article on 'sensation seekers' ranks as one of
the 50 most influential works in the history of psychology--
along with work by such renowned researchers as Sigmund
Freud, B.F. Skinner, Jean Piaget and others--in the newly
released book, "Notable Selections in Psychology," compiled
by Terry F. Pettijohn.
     Zuckerman's article, "Dimensions of Sensation Seeking,"
describes a comprehensive personality-assessment tool known
as the Sensation-Seeking Scale (SSS). By prompting
respondents to agree or disagree with such statements as, "I
sometimes like to do things that are a little frightening"
and "I like doing things just for the thrill of it," the SSS
helps psychologists gauge sensation-seeking tendencies. A
personality category first identified by Zuckerman in 1964,
sensation seekers crave "varied, novel, complex and intense
sensations and experiences," he explained.
     Zuckerman's studies of sensation seekers have had "a
profound impact on our understanding of personality traits,"
said book editor Pettijohn, a psychology professor at Ohio
State University. "I have admired Marvin's work for many
years, and so I was delighted to include one of his papers
in my book."
     The honor was the latest example of Zuckerman's status
as a leading authority on personality, according to Thomas
R. Scott, associate dean of the UD College of Arts and
Science. "Marvin was also recently listed as the 12th most
cited social or personality psychologist, meaning that other
researchers frequently refer to his works," he said. "Freud
was first on that same list of 100 authors, which was
published by the Personality and Social Psychology
Bulletin."
                              
               In search of sensation seekers

     The first version of Zuckerman's Sensation-Seeking
Scale, created more than 30 years ago, was designed to
predict an individual's response to sensory deprivation.
Since then, the personality-assessment tool has been refined
to gauge four key tendencies: thrill and adventure seeking;
experience seeking; disinhibition; and susceptibility to
boredom.
     "Thrill seekers" get a kick out of activities or sports
that provide unusual sensations and experiences--even if
they involve risk. Motorcycle racing or water-skiing, for
example, might appeal to this category of sensation seekers,
Zuckerman explained in the "Encyclopedia of Psychology"
(1994, Wiley Interscience). "Experience seekers" enjoy novel
experiences--say, travel to exotic locations, listening to
unusual or exciting music, experimenting with drugs or
living a "non-conformist" lifestyle, Zuckerman said.
"Disinhibitors" are constantly searching for opportunities
to lose their inhibitions at "wild" parties involving heavy
drinking and sexual activities with strangers, he added.
Finally, sensation seekers are very easily bored by
repetitious, predictable experiences and people, or by
routine work assignments.
     In general, Zuckerman said, men usually demonstrate a
stronger overall sensation-seeking tendency than women.
People who have been divorced score higher, on average, than
married or single people. Sensation-seeking behaviors seem
to peak among those in their late teens and early 20s, and
they decline with age in both men and women. People who
regularly practice a conventional religion are more likely
to be classified as low sensation seekers.
     The Sensation Seeking Scale has been used to identify
teenagers who may be jeopardizing their health and safety by
using drugs, engaging in frequent sexual activity with many
partners, driving recklessly or under the influence of
alcohol. With researcher Paula Horvath, Zuckerman reported
in 1993 that sensation-seeking tendencies among college
students (as measured by the SSS)--and reports of sensation-
seeking behaviors among peers--were strong predictors of
their own risky behavior, especially criminal activity and
social violations.
     Zuckerman's analytical techniques might also be used to
develop the teaching methods best suited to children's
individual learning styles, or to match job assignments with
employees' personality traits. "High sensation seekers like
risky or even periodically stressful vocations, like air
pilots, air-traffic controllers, emergency-room hospital
workers or occupations providing a great deal of varied
social contacts," Zuckerman said. "They're dissatisfied and
bored by routine, repetitious jobs that don't involve social
interaction or challenging and changing activities. When
high sensation seekers are mismatched in such jobs, they
often turn to alcohol and drugs, instead of healthier
alternatives such as sports, to compensate for the dullness
of half their waking hours."
                              
                   Nature? -- Or Nurture?

     For psychologists, the ages-old question is whether
personality traits are primarily influenced by nature--
genetically inherited physiological characteristics and
biochemicals in the brain--or "nurture" in the form of
childhood experiences. In the 1970s, Zuckerman and research
associates in England sought to answer this question by
comparing sensation seeking among identical twins, whose
genetic profile is identical, and fraternal twins, who share
half their genes. Among a sample of British twins, Zuckerman
said, 60 percent of their similarity on the sensation-
seeking trait could be attributed to genetic factors--a
surprisingly high figure for personality traits. A
subsequent study of Minnesota twins who were separated at
birth, or shortly after birth when they were adopted into
different families, yielded the same estimate of genetic
influence, even though the subjects did not share a common
environment during their formative years (Lykken, 1992,
"Personal Communication").
     This last year, two different sets of investigators in
Israel and at the National Institute of Mental Health in the
United States independently discovered one of the specific
genes associated with the sensation-seeking personality
trait, Zuckerman said. The gene produces D4, a dopamine
receptor in the brain. In 1979, Zuckerman had hypothesized
that dopamine--a neurotransmitter that mediates nerve-cell
transmissions--might be involved in sensation seeking, in
part because several researchers had found that people with
high brain levels of an enzyme called monoamine oxidase
(MAO) are less likely to be sensation seekers.
     The "type B" MAO enzyme plays a key role in regulating
certain neurotransmitters, particularly dopamine. Zuckerman
said he believes that high dopamine activity, or a large
number of dopamine receptors, may be characteristic of
sensation seekers. Certain strains of rats exhibiting
sensation seeking-like behaviors have high levels of
dopamine, he noted. Moreover, dopamine is known to mediate
the craving for stimulant drugs in humans and animals, and
sensation seekers are prone to drug use.
     Along with dopamine, other neurotransmitters also may
be involved in sensation seeking. Low activity in serotonin,
for instance, may account for a lack of inhibition and
impulsiveness among many sensation seekers, and low
noradrenergic reactivity could account for the fearlessness
of sensation seekers in risky situations.
     Zuckerman's search for the genetic and biochemical
bases of sensation-seeking behaviors will continue during
his upcoming sabbatical, when he plans to work in the
molecular genetics laboratory of Robert Plomin at the
Maudsley Institute of Psychology in London. They will be
searching for additional genes connected with impulsive
sensation seeking, as well as other personality traits.
     Zuckerman joined the UD faculty in 1969. He received
his Ph.D. from New York University in 1954 and held
positions at such institutions as Adelphi University,
Brooklyn College and the Albert Einstein Medical Center
(Philadelphia). Past president of the International Society
for the Study of Individual Differences, he has earned
several UD honors, including a research fellowship in the
Delaware Institute for Advanced Studies and a distinguished
lectureship in the College of Arts and Science. He also held
a research fellowship at the Netherlands Institute for
Advanced Studies during the 1990-91 academic year. He
recently published his fifth book, "Behavioral Expressions
and Biosocial Bases of Sensation Seeking." His previous
book, "Psychobiology of Personality," has received wide
attention in the field of personality psychology.
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Contact:  Ginger Pinholster
          Jan. 16, 1997