July 25, 2005 -- Does your résumé reveal your odds of having good health?
New research shows that identical twins in "professional" jobs were in better health than their twin in "working-class" jobs.
Of course, job status doesn't always mirror health. Plenty of people in powerful positions face serious conditions. Many workers across the economy are healthy.
The study was done by Nancy Krieger, PhD, and colleagues. Krieger is an associate professor in the department of society, human development, and health of the Harvard School of Public Health.
The results appear in Public Library of Science Medicine.
Twin studies are often done to probe how genes and environment affect health. Since identical twins share the same genes and are often raised together, they provide a unique window on those influences.
Krieger's study included 130 pairs of identical twins and 178 pairs of nonidentical twins. All of the twins were women living in and around San Francisco. They were listed in a registry of twins in northern California.
Each set of twins had been raised together until age 14. After that, their lives had taken different paths.
The twins' childhood social-economic class, education level, and adult careers were noted. The researchers grouped career type as "professional" or "working class."
Professionals supervised others, were self-employed, or were business owners with employees. "Working class" referred to employees who weren't supervisors.
The researchers noticed differences among the 51 sets of identical twins in which one twin was a professional while the other had a working-class job.
In those cases, the professionals tended to have better blood pressure and cholesterol than their working-class identical twins, write the researchers.
"The working-class twin typically fared worse than the professional twin" for those heart health tests, write Krieger and colleagues.
"Excellent" or "good" health was more often reported by identical twins in professional jobs. Identical twins in working-class jobs more often reported "fair" or "poor" health.
The same patterns weren't seen with education level or among nonidentical twins, write the researchers.
Did the trend stem from wealth? It's hard to say. The researchers also didn't have information on the twins' wealth or debt, which don't always match a worker's paycheck.