People’s preference for simple explanations of any situation is connected to their desire to execute tasks efficiently, finds a new study from the University of Waterloo.

“These findings show that our preference for simpler explanations mirrors how we evaluate actions. Simplicity isn’t just valued in explanations—it’s part of how we think about achieving results efficiently,” said Claudia Sehl, lead author and a PhD candidate in developmental psychology at Waterloo.

Sehl collaborated with Waterloo developmental psychology professors Ori Friedman and Stephanie Denison on this study. They conducted seven experiments involving 2,820 participants who were presented with simple and complex ways to explain an outcome or achieve a goal. Participants consistently favoured the simpler options.

The study found that people are more attracted to explanations that involve common and reliable causes. If a cause seemed rare or unreliable, it was viewed as less helpful. In other words, the simpler and more dependable the cause, the more appealing it was both for understanding an event and for achieving results in the future.

“Essentially, the more common and reliable a cause, the more appealing it became as both an explanation and a method for achieving outcomes,” Sehl said. “Additionally, whether describing causes or seeking outcomes, using fewer causes seems both faster and more effective, pointing to a shared mental process behind both preferences.”

Overall, the findings suggest that efficiency is valued both in explanations and when achieving goals.

“Our research suggests that people care a lot about efficiency—the idea of doing more with less—and that this focus on efficiency affects how people think about both explanations and accomplishments,” Friedman said.

This study, Doing things efficiently: Testing an account of why simple explanations are satisfying, by Sehl, Friedman, and Denison, is published in Cognitive Psychology.