Human ideas improved without discarding weaker designs in experiment

Petr Tureček of the Department of Philosophy and History of Science and the Center for Theoretical Study at Charles University explained:

“It turned out that the gradual acceleration of our 3D objects on the inclined track was not caused by selecting the best pieces, but by the participants' ability to understand the underlying principle of the problem and improve it in their minds even before the physical attempt.”

Tureček added a statistical qualification:

“As far as we can statistically distinguish given the sample size, generational chains where selection was not applied improved at the same rate as chains with selection.”

The caveat matters because the team could not statistically distinguish the two improvement rates. The finding shows that discarding weaker designs was unnecessary for these gains; it does not show that selection can never assist cultural change.

This pattern fits guided variation, a cultural-evolution term for changes directed by a person's understanding rather than random trial and error alone. It treats an inherited idea as something people reconstruct mentally before producing the next physical version.

Understanding the principle, rather than simply removing weak versions, carried the technical gain in this experiment.

What differed between Czechia and Cameroon?

Robert Mbe Akoko and his team at the University of Buea enabled field collection in Cameroon and provided information about local community practices and the social setting.

Doctoral students Peter Kutsos, who began the project as part of his master's thesis, and Petr Chlup compared Prague students with university students in Buea's Molyko neighborhood and members of the traditional Bakweri community from Bokwango.

Cameroonian participants generally followed the supplied models less closely and systematically departed farther from the average. Czech participants preserved the core structure more faithfully in both engineering and the average-artifact control. In the aesthetic task, each Czech participant tended to develop a distinctive personal style.

The authors concluded that the cultural environment in which a person grows up can shape the style of innovation more strongly than the person's level of formal education.

Cultural setting shaped how closely makers followed a model and how they personalized it.

Why do diverse examples matter?

For decades, scientific models of cultural evolution borrowed assumptions from genetics, including the idea that variation among human ideas stays constant across generations. Variance, in plain terms, means how widely outputs differ from one another.

The team found that people who observed diverse models tended to create more varied outputs. The tendency did not necessarily occur in every individual. But among those who showed it, a statistical model that allowed output diversity to scale with input diversity outperformed competing models across engineering, aesthetics and the average-artifact control.

The authors therefore described human culture as creative reconstruction rooted in the mind, not merely copying with errors. Diverse starting points could widen the range of later ideas.

The results appear under the title “The shape of the cultural transmission of shapes,” with Peter Kutsos listed first among the authors. The citation gives a 2027 publication year in Evolution and Human Behavior and the DOI 10.1016/j.evolhumbehav.2026.106994.

What does this change for practitioners?

For practitioners running design teams or learning exercises, the study shifts attention toward how people reason about a task and how much variety they encounter, rather than treating ranking and elimination as the only engines of improvement.

The evidence still has boundaries. It comes from one study of 600 participants in two countries and three tasks, and the researchers could not statistically separate selected from unselected chains at this sample size.

The broader conclusion is narrower: technical ideas improved when people grasped the governing principle, while aesthetic ideas remained open to different cultural and personal directions.

Technical progress gained momentum from understanding and guided variation, even without weeding out weaker designs.