By Sarah Green Carmichael
A large body of research suggests that regardless of our reasons for working long hours—demanding bosses, financial incentives, personal ambition–overwork does not help us.
For starters, it doesn’t seem to result in more output. In a study of consultants by Erin Reid, a professor at Boston University’s Questrom School of Business, managers couldn’t tell the difference between employees who actually worked 80 hours a week and those who just pretended to. While managers did penalize employees who were transparent about working less, Reid was not able to find any evidence that those employees actually accomplished less, or any sign that the overworking employees accomplished more.
Considerable evidence shows that overwork hurts us and the companies we work for. Numerous studies by Marianna Virtanen of the Finnish Institute of Occupational Health and her colleagues (as well as other studies) have found that overwork and the resulting stress can lead to all sorts of health problems, including impaired sleep, depression, heavy drinking, diabetes, impaired memory and heart disease. Of course, those are bad on their own. But they’re also terrible for a company’s bottom line, leading to absenteeism, turnover and rising health insurance costs.
Researchers have found that overwork (and its accompanying stress and exhaustion) can impede interpersonal communication, making judgment calls, reading other people’s faces and managing your own emotional reactions—all things that the modern office requires. Even if you enjoy your job and work long hours voluntarily, you’re simply more likely to make mistakes when you’re tired. Only 1 percent to 3 percent of the population can sleep five or six hours a night without suffering some performance drop-off. Work too hard and you also lose sight of the bigger picture. Research suggests that as we burn out, we have a greater tendency to get lost in the weeds.
In sum the story of overwork is one of diminishing returns: Keep overworking, and you’ll progressively work more stupidly on tasks that are increasingly meaningless.
Now, this isn’t to say we can never pull a long day. We just can’t do it routinely. Most of the research I’ve seen suggests that people can put in one or two 60-hour weeks to resolve a true crisis. But that’s different from chronic overwork.
Sarah Green Carmichael is a senior associate editor at Harvard Business Review.