Figures as different as Charles Dickens, Henri Poincaré, and Ingmar Bergman, working in disparate fields in different times, all shared a passion for their work, a terrific ambition to succeed, and an almost superhuman capacity to focus. Yet when you look closely at their daily lives, they only spent a few hours a day doing what we would recognize as their most important work. The rest of the time, they were hiking mountains, taking naps, going on walks with friends, or just sitting and thinking. Their creativity and productivity, in other words, were not the result of endless hours of toil. Their towering creative achievements result from modest “working” hours.
Illinois Institute of Technology psychology professors Raymond Van Zelst and Willard Kerr surveyed their colleagues about their work habits and schedules, then graphed the number of hours faculty spent in the office against the number of articles they produced. You might expect that the result would be a straight line showing that the more hours scientists worked, the more articles they published. But it wasn’t. The data revealed an M-shaped curve. The curve rose steeply at first and peaked at between 10 to 20 hours per week. The curve then turned downward. Scientists who spent 25 hours in the workplace were no more productive than those who spent five. Scientists working 35 hours a week were half as productive as their 20-hours-a-week colleagues.
From there, the curve rose again, but more modestly. Researchers who buckled down and spent 50 hours per week in the lab were able to pull themselves out of the 35-hour valley: They became as productive as colleagues who spent five hours a week in the lab. Van Zelst and Kerr speculated that this 50-hour bump was concentrated in “physical research which requires continuous use of bulky equipment,” and that most of those 10-hour days were spent tending machines and occasionally taking measurements.
After that, it was all downhill: The 60-plus-hour-a-week researchers were the least productive of all.
Van Zelst and Kerr also asked faculty how many “hours per typical work day do you devote to homework which contributes to the efficient performance of your job” and graphed those results against productivity as well. This time, they didn’t see an M but rather a single curve peaking around three to three and a half hours a day. Unfortunately, they don’t say anything about total hours spent working at the office and home; they only allude to “the probability that” the most productive researchers “do much of their creative work at home or elsewhere,” rather than on campus. If you assume that the most productive office and home workers in this study are the same, this cohort is working between 25 and 38 hours a week. In a six-day week, that works out to an average of four to six hours a day.