Following the New York Times article last week about Amazon, tech workers from other companies were quick to point out that the 80-hour work week expectation is simply part and parcel of the industry. Dustin Moskovitz, one of the founders of Facebook and current CEO of workplace collaboration start-up Asana, wrote an essay titled, “Work Hard, Live Well: Amazon isn’t the only company burning out their employees with unsustainable expectations. Let’s break the cycle.”

His argument, which used to be accepted (because it’s proven) wisdom: Return to the 40-hour work week. People who work more than that don’t yield much, in fact, they produce less.

Reflecting on his experience, Moskovitz recalls 2006 as “a great year for Facebook, one of the worst years for me as a human.” He describes drinking more soft drinks than water, and often going without sleep or food; panic attacks, petty fights, frustration, etc. Moskovitz sees in hindsight that he would have been a better, more effective manager and a happier and healthier person, if there had been some balance in his work life.

“Many people believe that weekends and the 40-hour workweek are some sort of great compromise between capitalism and hedonism, but that’s not historically accurate,” Moskovitz writes.

Moskovitz cites the classic, but as he notes, apparently forgotten, research conducted by Henry Ford — conducted to maximize profits — which determined that businesses could actually get more output out of people by having them work fewer days and fewer hours. (And doubling their pay.) It led to the 40-hour work week, which unions were quick to champion. Businesses followed, because it made sense. (Ford’s research has been confirmed through other studies, decade after decade.)

Since tech companies thrive on metrics, it would seem such research about productivity would be reflected in their workplaces. These, of course, aren’t workers on an assembly line. (Those workers are in China.) But the “rest is important” theory applies even more so to those with jobs requiring creativity. In a 2006 Salon article calling for the return of the 40-hour work week, Sara Robinson notes that so-called “knowledge workers” actually have fewer good hours in a day than manual laborers do — on average, about six hours.

The 80-hour work week, in other words, is detrimental to business.

Robinson writes: “The Business Roundtable study found that after just eight 60-hour weeks, the fall-off in productivity is so marked that the average team would have actually gotten just as much done and been better off if they’d just stuck to a 40-hour week all along. And at 70- or 80-hour weeks, the fall-off happens even faster: at 80 hours, the break-even point is reached in just three weeks.”

So much of our technology boom, and the accompanying products, feels so new and futuristic and never-experienced-before, that it’s easy to dismiss research that started with Henry Ford as irrelevant. But, in reality, it’s more relevant than ever.

Tech companies can get so much more from their employees, by demanding less of their time Much less.