DURHAM, N.C. -- Men who monopolize conversations, interrupt others and excessively compete for attention -- a personality trait known as social dominance -- have a higher rate of early death than men who have a more relaxed approach to communicating, according to Michael Babyak, a researcher at Duke University Medical Center.
In a 22-year study of 750 white, middle-class men, Babyak and his colleagues at three other institutions found that men who were identified as socially dominant were 60 percent more likely than the other subjects to die of all causes during the study period. Babyak and lead investigator the late B. Kent Houston conducted the study while at the University of Kansas in conjunction with colleagues from the University of California at Berkeley and at San Francisco (UCSF).
Results of the study are published in the Jan. 23 issue of the Journal of the American Psychosomatic Society.
The researchers say theirs is the first study to calculate the long-term health risks of social dominance, a behavior that is distinctly different from being gregarious and outgoing. Until now, Type A behavior and hostility have been the major personality traits that science has strongly linked to adverse health, said Babyak, an assistant clinical professor of medical psychology at Duke.
The new study suggests that social dominance by itself is as much of a risk factor as hostility. Conversely, men who spoke calmly and quietly had lower than normal rates of heart disease and early death compared to all other personality subgroups in the study.
"We don't know why this effect exists, but we theorize that socially dominant men are more chronically aroused and stressed, so they release more of the damaging stress hormones," said Babyak, whose co-authors include Margaret A. Chesney and George Black, UCSF; David Ragland, UC Berkeley; and Houston. Babyak said it could also be that the same gene or genes that influence socially dominant behavior -- if such genes exist -- also cause heart disease and other illnesses that lead to an early death, but such a theory is still speculative.
While social dominance and hostility are both traits of the Type A personality, Babyak said the two behaviors are different. Hostility is often a tool that dominant people use to get their way,
but dominant behavior can be an attempt to control without necessarily using hostility.
"Interestingly, socially dominant women may be at less health risk than socially dominant men because dominance may mean something different for women," he said. "In men, dominance appears to involve getting ahead of other people strictly for the sake of getting ahead, and that seems to be a key aspect of its danger."
In women, however, dominance generally means gathering more support for one's cause and collaborating instead of competing.
Babyak says that social dominance is not the same thing as being excessively outgoing or achievement-oriented because dominance is driven by feelings of insecurity whereas the latter traits are driven by self-confidence and the desire for personal fulfillment. Socially dominant people tend to be attention-seekers who are trying to get ahead at the expense of others and are struggling to prove their self worth.
To identify socially dominant men, the researchers conducted interviews with each subject, then scored them on 12 speech and behavior characteristics, including verbal competitiveness, exactingness, speaking rate, loudness, hostility and self-aggrandizement. Subjects were grouped into six different categories based on how they responded during the structured interview. The researchers then calculated the relationship between each personality category and its overall health and survival rate over a 22-year period.
After controlling for health risks such as smoking, blood pressure and cholesterol, the researchers found that socially dominant people were still about 60 percent more likely than all the other subjects to die of any cause. Hostile people had roughly the same risk as socially dominant people, Babyak said.
"Social dominance by itself is a moderate risk factor for early death, but it takes on even more significance when you combine it with other high-risk behaviors such as smoking, a poor diet and a sedentary lifestyle," he said. "Clearly, if you have these personality characteristics, it wouldn't hurt to modify them."
As with other personality traits, researchers don't know if social dominance is genetically or environmentally determined. But regardless of its origins, people can still lower their risk of disease and death by modifying their behavior.
"Most personality traits have some genetic basis, but the environment can play a strong role in the extent to which the trait is expressed," Babyak said. "So changing your behavior can modify your body's response to the trait." Babyak compares it to the effect of a low-fat diet and exercise on reducing one's risk of heart attack, even in a person who is genetically prone to heart disease.
The study is based on an earlier study led by Drs. Ray Rosenman and Meyer Friedman, who pioneered research on Type A behavior. Dr. Michael Hecker was instrumental in developing the procedure for scientifically analyzing the speech and behavior characteristics of the interviews.