Several years ago, the scientist and author Leidy Klotz was building a bridge out of Legos with his son when he noticed that one of the bridge’s supports was longer than the other. Klotz began to search for more bricks to add to the shorter end, but his son came up with a faster, more elegant solution: simply removing a brick from the taller end. 

“I wouldn’t have thought about subtracting if my son hadn’t been there,” says Klotz, a professor of engineering and architecture at the University of Virginia. It inspired him to take a closer look at what he calls subtraction neglect, the seemingly universal human tendency to favor adding over subtracting when confronted with solving a problem. In Klotz’s research, using Legos in varying configurations or grid patterns on computer screens, participants overwhelmingly chose to add things—even when subtracting would have solved the problem much more quickly and easily. Like Klotz, the idea of subtracting simply never occurred to them. 

Klotz has several theories on why this might be: From a “building civilization” standpoint, adding things, like food or shelter or roads, is generally a plus. And then there’s the matter of ego. When Klotz’s subjects were asked to improve a piece of writing, they were more inclined to add an extra line or two, especially when it was their own writing they were asked to polish. “It’s like that Stephen King quote about killing your darlings,” he says. “Those are your darlings that you’ve written, or built.” 

An encouragement to subtract can be seen in various forms of the so-called slow movement, which include calls to reduce the length of the standard workweek from five days to four. The idea is a good one, but as Cal Newport argues in Slow Productivity: The Lost Art of Accomplishment Without Burnout, many employees aren’t burdened by how many hours they work, but by how much work they’re expected to do during them. What we need, Newport says, is to rethink how we measure productivity—as well as to reduce the volume of work employees have to do in the first place.