Psychology: People overlook subtractive improvements

When asked to improve objects, ideas and situations, people tend to add extra elements rather than removing them, a Nature study reveals. As a result, additive solutions to problems may be accepted without considering potentially superior alternatives that involve subtracting elements.

Improving objects and ideas — such as developing a technology or strengthening an argument — can be done either by adding novel features, or by subtracting to streamline the object or idea. However, to manage the fatigue of searching through all of the possible options, people tend to limit the number of ideas that they consider, often leading to suboptimal solutions.

In experiments involving 1,153 participants, Gabrielle Adams, Benjamin Converse and colleagues looked at the way people responded to a diverse array of problems, including solving a geometrical puzzle, stabilizing a Lego structure and improving a miniature golf course. They found that the participants tended to favour additive solutions, and routinely overlooked subtractive options, even when the latter offered simpler and better solutions.

Follow-up experiments suggest that subtractive changes are cognitively less accessible to people, and so the default strategy becomes one of addition. The authors conclude that this may be one reason why people struggle to mitigate problems such as overburdened schedules, institutional red tape and damaging impacts on the planet.

After the embargo ends, the full paper will be available at: https://www.nature.com/articles/s41586-021-03380-y