Individuals with eating disorders possess certain personality traits, some
studies have suggested. For example, individuals with anorexia nervosa were
found to score high on persistence, whereas binge eaters were found to score
high on novelty seeking.
And now a new study, reported in the April International Journal of
Obesity, has not only strongly linked novelty seeking with obesity, but
with difficulty in losing weight.
The study was conducted by C. Robert Cloninger, M.D., a professor of
psychiatry and genetics at Washington University in St. Louis, and colleagues.
Cloninger was one of the developers of the Temperament and Character Inventory
(TCI), which measures seven dimensions of personality—novelty seeking,
harm avoidance, reward dependence, persistence, self-directedness,
cooperativeness, and self-transcendence. Cloninger and his colleagues also
used the TCI as their yardstick in this study.
The TCI was used to assess the personalities of 264 lean and 56 obese
people living in the St. Louis area, as well as 183 obese individuals enrolled
in the Washington University Weight Management Program, which involved weekly
group-behavioral therapy and diet-education sessions for 22 weeks.
The researchers compared the personalities of the obese subjects in the
community with those of the lean subjects, the obese subjects enrolled in the
weight-management program with obese people in the community, and the
weight-managementprogram enrollees who managed to lose more than 10 percent
of their weight with those who did not.
The comparisons revealed some statistically significant differences in
personality characteristics between the groups. Specifically, when obese
subjects in the community were compared with lean subjects there, the former
scored significantly higher in novelty seeking, significantly lower in
persistence, and significantly lower in self-directedness. Obese subjects
enrolled in the weight-management program scored significantly higher than did
obese subjects in the community on both reward dependence and cooperativeness.
And subjects in the weight-management program who managed to lose more than 10
percent of their weight scored significantly lower on novelty seeking than did
those in the program who failed to lose that much weight.
In sum, "these data suggest that specific personality characteristics
are involved in the pathogenesis of obesity," Cloninger and his group
In their report, they also discussed some of the practical implications of
For example, because novelty seeking was strongly associated with obesity
in the general population and with obese individuals' difficulty in losing
weight, "high novelty-seeking scores indicate a strong appetite
drive," they noted.
People who are self-directed are able to set and pursue meaningful goals.
Because obese subjects scored lower on self-directedness than lean subjects
did, their difficulty in losing weight may partially stem from their
difficulty in setting and pursuing goals.
Reward-dependent individuals, according to the TCI, tend to be emotionally
warm and sociable and to need social approval. Obese individuals enrolled in
the weight-loss program tended to fall into this group. So the reason why they
enrolled in the program may be because they had no aversion to being part of a
group and because they were eager to lose weight and reap social approval for
The study results might also be used to help obese people lose weight,
Cloninger and his team speculated. For example, personality characteristics
might be used to identify patients in advance who can benefit from behavioral
weight-loss therapy. Or weight-loss programs might be designed to take into
consideration the personality traits of their clients.
"This study adds to growing evidence that neuropsychological factors
play an important role in causing obesity, which is one of the largest public
health problems facing our society," James Hudson, M.D., Sc.D., a
professor of psychiatry at Harvard University and an eating-disorders expert,
told Psychiatric News. In 2005, in fact, Hudson predicted that"
neuropsychological factors are going to emerge as one of the important
causes of obesity" (Psychiatric News, September 16, 2005).
The investigation is "indeed very interesting," Michael Devlin,
clinical co-director of eating disorders research at the New York State
Psychiatric Institute, commented. "Regarding the comparison between
obese and normal-weight individuals, I think it demonstrates pretty
convincingly that there are aspects of temperament and character that may be
associated with obesity. This is not to say that there is an `obese
personality type.' Rather, it may be that some particularly high or low scores
on certain dimensions of temperament or character—and the corresponding
neurobiological patterns—may, in combination with other genetic and
environmental factors, contribute to an individual's predisposition to obesity
or to the full expression of her or his potential for obesity."
The study was funded by the National Institutes of Health.
An abstract of "Personality Characteristics in Obesity and
Relationship With Successful Weight Loss" is posted at<www.nature.com/ijo/journal/v31/n4/abs/0803464a.html>.▪