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Adding complexity when we should be subtracting it

Illustration imagining a person's head containing more plus than minus signs, symbolizing how we default to additive changes.
Gary Neill

The architect Ludwig Mies van der Rohe might have famously observed that “Less is more,” but when it comes to problem-solving and solution-seeking, our brains may default toward additive rather than subtractive changes. Whether it’s the proliferating features on our phones, ideas to improve an organization or our endless to-do lists, “We tend not to ask ourselves what can we take away from it, what can we subtract, what can we remove that might still make something better,” says UVA assistant professor Gabrielle Adams.

This is the argument put forth in a recent paper in the journal Nature by a team of UVA researchers that included Adams, associate professors Benjamin Converse and Leidy Klotz, and former post-doctoral researcher Andrew Hales. Over a series of observational and experimental studies, the researchers found that when tasked with changing an object, idea or situation—such as solving a 3D puzzle, editing a document, or changing a hole on a mini-golf course—people were significantly more likely to come up with additive changes. For example, they were more likely to add than remove words from the document, and in a Lego construction challenge, they were more likely to add pieces even when the challenge could more quickly be solved by removing just one piece.

These results, the researchers suggest, may indicate that additive changes are a kind of cognitive shortcut that allows our brains to reduce the number of ideas to be generated.

However, the researchers also found that prompts, nudges and incentives could increase the likelihood that participants would consider subtractive changes. These prompts included explicitly reminding participants that subtraction was an option or putting a cost (10 cents) on adding parts while making removing parts free. Similarly, when participants were given several practice trials before solving a puzzle, they were more likely to find the subtractive solution.

Suggesting that “the tendency to overlook subtraction may be implicated in a variety of costly modern trends,” the writers argue that in defaulting to additive transformations, people “may be missing opportunities to make their lives more fulfilling, their institutions more effective, and the planet more livable.”