K.I.S.S. is, besides a band that played its last concert and now will continue as holograms, a basic principle that often suits your presentations or anything else: keep it simple, stupid. A new study also shows another connected reason: People’s preference for simple explanations of any situation is connected to their desire to execute tasks efficiently.

The study as described in short:

• We examined why people prefer simple explanations.

• We suggest the preference arises because people value completing goals efficiently.
• Participants evaluated the appeal of explanations and causal processes.
• Participants generally preferred simple methods as both explanations and processes.
• Statistical information diminished and reversed this preference in parallel for both judgments.

From the press release:

“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.

Abstract of the study:

People often find simple explanations more satisfying than complex ones. Across seven preregistered experiments, we provide evidence that this simplicity preference is not specific to explanations and may instead arises from a broader tendency to prefer completing goals in efficient ways. In each experiment, participants (total N=2820) learned of simple and complex methods for producing an outcome, and judged which was more appealing—either as an explanation why the outcome happened, or as a process for producing it. Participants showed similar preferences across judgments. They preferred simple methods as explanations and processes in tasks with no statistical information about the reliability or pervasiveness of causal elements. But when this statistical information was provided, preferences for simple causes often diminished and reversed in both kinds of judgments. Together, these findings suggest that people may assess explanations much in the same ways they assess methods for completing goals, and that both kinds of judgments depend on the same cognitive mechanisms.