Increasingly, researchers have been turning to identical and fraternal twins for answers, with dramatic results. They are finding that genetics, in addition to familial interests, educational, social and other environmental pressures, have a considerable impact on how we choose what we do—and how happy we are with that choice.
Twins reared apart, one University of Minnesota study showed, chose jobs that were similar in terms of complexity level, motor skills and physical demands. In other studies, twins have been shown to have similar tendencies when it comes to "enterprising," "conventional" and "artistic" undertakings; they also share basic interests, be they science, the pastry arts or public speaking. In both sets of measurements, the similarities between identical twins are greater than between fraternal twins.
Is Everybody Happy?
But it's not only the content of our work that is influenced by genes. Studies with twins have shown us that our satisfaction on the job may be at least 30 percent attributable to genetic factors. This finding is intriguing because it seems to be related to "intrinsic job satisfaction"—questions of challenge or achievement—rather than "extrinsic" factors such as work conditions or supervision. In other words, internal rewards that come from teaching students or composing music, for example, affect the twins' job satisfaction in more similar ways than working late hours or having an irate boss. This makes it easier to understand why identical twins reared apart chose similar occupations—their matched genetic predisposition probably steered them toward tasks at which they both excelled and which brought them joy, pride and satisfaction. People in general may, therefore, better understand their level of job satisfaction in terms of how well their abilities and opportunities coincide.
People bring a unique predisposition or set of expectations to the workplace that may be harder to modify than previously thought. And though tinkering with the lighting or buying a better printer or hiring companionable staff may improve job satisfaction, it may not help as much as one might hope. These same genetically influenced tendencies, in more "satisfied" types, may help explain why some people persist at interesting or fulfilling jobs even when they offer only modest pay or slim hopes of advancement. When we like what we do we may be more tolerant of troubles that arise from time to time in any work.
Job satisfaction may also partly be affected by our characteristic happiness levels. Recent twin research showed that the genetic contributions to happiness and stability are about 50 percent and 80 percent, respectively, while life events have only a transitory effect on happiness. How does this work on the job? A bonus may momentarily elevate the satisfaction of an upbeat worker, but is unlikely to sustain it. Longer coffee breaks may lighten the loathing of a despondent employee, but won't alter his outlook for long. Moreover, two individuals with equally well-matched talents and tasks may vary in job satisfaction if one is typically happy and the other is typically depressed.
Hitting the Road
Have you been with your company 20 years? Changed employers every six months? It may be partly in the genes. In twin studies, genetic factors explained 36 percent of why individuals switch jobs, and 26 percent of why they change careers.
Formal studies define the factors affecting job choice and satisfaction. They cannot, however, capture the unique personal decisions and unforeseen events that all of us face when fashioning our careers. An in-depth look at the lives of prominent identical and fraternal twins may help bring these fascinating details into sharper focus.
The Unplanned Presidents
"A Pair of Presidents Keep It All in the Family" was the headline of a 1995 New York Times article. As I read, I found fascinating and compelling beyond words the rare matched achievements of Harold T. Shapiro, president of Princeton University, and his brother, Bernard J. Shapiro, principal (the Canadian equivalent of president) of McGill University in Canada. Becoming a university president is a position held by so few people that to find it repeated by identical twins suggests that the twins' genetic abilities and personalities were contributing factors.
I met Harold in his office at Princeton University. His warm and gracious manner promised sincere and thoughtful dialogue on his twinship and career. His office was the epitome of neatness and order, strikingly different from the typically cluttered halls of academia. I saw only one other such office—the one belonging to Bernard. Bernard also welcomed me personally, showing the same friendliness and grace. Opera music played in the background, an interest the twins share. Bernard believes his twin has more natural talent, but said, "I was a better musician because I practiced."
Indeed, more than their differences, the Shapiros, like many identical twins, presented unique versions of the same score:
o In 1961, both twins entered top graduate schools, but in different fields. Harold attended Princeton University in economics, and Bernard attended Harvard University in education. Both chose statistical specializations, prompting Harold's comment: "Something is going on here. I recognize long odds when I see them."
o Harold earned his Ph.D. in 1964, becoming assistant professor of economics at the University of Michigan. Bernard received his Ed.D. in 1967, becoming assistant professor of education at Boston University. The twins served as university provosts in partially overlapping years, Harold at the University of Michigan and Bernard at the University of Western Ontario in Canada. Harold initially declined the presidency of Princeton, and Bernard initially declined the presidency of McGill. Both universities pursued their candidates, who eventually accepted second offers. Both twins also are the first Jewish presidents of their universities.
Challenge and change draw many people to new jobs. However, the Shapiros never mentioned status as a factor affecting their career choices, something many people would consider important. I also noticed that neither twin expressed regret at sacrificing his personal research programs for administrative responsibilities, something many academics (including myself) find surprising.
Paradoxically, the Shapiros' different routes to university presidency were similarly unconventional. Neither twin sought the highest post in his academic institution, but opportunities came their way. A boyhood friend observed that while neither twin entertained presidential ambitions, they probably asked the same important questions when the offers came: Is this job interesting? Could I make a contribution? Would I do it well?
Physicians, Not Farmers
Drs. Judith and Julie Swain replay themes brought out by the Shapiro twins. Each holds the chair of the cardiology department in her respective university, a demanding position that few people—and fewer women—attain.
Judith and Julie Swain were born in 1948 in Cypress, Calif., the only children of Joe and Christine Swain. The twins' father was a salesman and their mother was a librarian. In 1994, at the age of 45, Judith became the only female chair of a major university's cardiology department, at the University of Pennsylvania, and the first female president of the American Society for Clinical Investigation. She is currently a professor and chair of the department of medicine at Stanford University in Palo Alto. Julie, her older sister by five minutes, was the first female chief of cardiac surgery in an American medical center, Louisiana State University, and is chair of the Food and Drug Administration's committee on circulatory system devices. She is currently a professor and associate director of the Kentucky Heart Institute at the University of Kentucky in Lexington.
The Swains saw their mother as a role model, someone who set high standards for her own accomplishments. According to Julie, "If we were farmers, we would be good farmers." They agree that their parents were not responsible for their medical interests, only for the high motivational levels that each twin brought to these interests. Indeed, each credits her career choice to the television shows Dr. Kildare and Ben Casey, in which fictional doctors saved lives. However, because parents provide both genes and environments for their children, the twins' motivations probably reflect a blend of both.
The twins' separate medical programs led to their only major career difference: their medical specialty. (Judith studied cardiology, Julie, cardiovascular and thoracic surgery.) But both told me that their medical areas are reflections of their mentors' interests and that each could easily imagine doing what the other sister does.
Personality parallels as well as similar skills seem to be driving the twins. Both work in their offices and laboratories from early morning until evening. Both twins chose not to have children, opting to care for cats instead. Some people might prefer a less frenetic lifestyle, but the twins thrive on this schedule. Clearly they chose careers commensurate with their outstanding intellect, boundless ambition and unlimited energy. (They both set aside time on weekends for sports activities, especially golf and polo.)
Julie's remark, "If we were farmers, we would be good farmers," is worth a second look. I believe she meant that both twins would do the best job possible regardless of the job. I agree, except that the job would have to fit the drive and direction that is essential to both twins' satisfaction. It may be no accident that the Swain sisters are not farmers.
Twist of Fate
Most people do not know that a twin walked on the moon. On April 16, 1972, identical twin Charlie Duke Jr. departed the Earth's atmosphere as a lunar module pilot on Apollo 16, becoming the 10th individual to reach the moon's surface five days later.
While Charlie was in transit, his family was allowed into mission control. When his brother Bill entered the medical laboratory, several staff members who did not know Charlie was an identical twin were shocked, believing he was thousands of miles away and hurtling ever deeper into space.
Why wasn't Bill buckled in along-side his brother? While it may be only part of the story, one physical difference between the twins had crucial consequences for their early development, twin relationship and professional goals: Bill was born with a heart defect. His shortness of breath and reduced exercise tolerance precluded his participation in active team sports. He also believes that his restricted physical activity and frequent medical visits explain his desire to become a physician.
The case of Charles and Bill Duke demonstrates that a major environmental event can alter genetic predisposition, leading twins to very different career paths. Bill's inability to join Charlie in athletic pursuits casts a shadow on their twinship. Bill resented being restricted from sports events and sensed parental favoritism toward his more physically fit twin. Their relationship included close moments, but was marked by friction.
I was fascinated by Charlie and Bill as twins because their apparent differences in occupation and life events disguise their fundamental similarities in intelligence and personality. Both twins obtained top grades in their (separate) high schools. They see themselves as "inquisitive, studious and goal-oriented, dedicated to doing the best job possible."
Charlie says he could imagine doing what his brother does because being a doctor would be "interesting and rewarding." Bill, on the other hand, realizes that his condition "colored" his world, making it "hard to say" if he might otherwise have joined his twin in space.
Same Nurture; Different Nature
Fraternal twins (who share approximately half their genes) present an informative contrast. Because they are raised in the same environment but are not genetically identical, they help us see the influence of environmental factors. David and Bill Koch are a marvelous lesson in just how modest family influences can be.
Brown-haired David Koch is a chemical engineer and executive vice-president of Koch Industries, the second largest closely held company in the United States. The diversified company, founded in 1940 by his father, operates oil refineries, manufactures chemicals and refining equipment, and owns large cattle ranges. David's fraternal twin, strawberry-blond-haired Bill, also had been involved in the company until business disagreements led to a series of courtroom battles between the brothers.
David and Bill Koch were born in 1940 in Wichita, Kan. Their behavioral differences emerged early. David was gregarious and athletic, Bill withdrawn and awkward; David was a good student from the start, Bill blossomed in high school and college; David's interests in people and activities were "mainstream," Bill's were "unusual." The boys competed in many ways, often engaging in unhealthy conflicts.
The twins' college years at MIT were their friendliest. Both majored in chemical engineering, like their father had; both joined the same fraternity and lived at the fraternity house; both also played college basketball. By 1963, both had received their master's degrees and by 1971, both were working for the family firm. But by 1980, they were no longer speaking—a far cry from the intimate and ongoing bond that many identical twins share.
"We could not be more different in our behaviors, personalities and interests," David said. "If the environment has a major influence we should be similar, but we are more different than alike."
Some people eagerly anticipate their daily work activities, while others spend hours watching the clock. Some people are a blend of the two, embracing certain aspects of their job and avoiding others. If we are dissatisfied with our work, it could be that our genetically influenced predisposition conflicts with the content and rewards of the job. If we want to be happy with our career, twin studies strongly suggest we pay close attention to our inner yearnings.