“Let me show why you are wrong”: The origins of scientific argumentation, its development, and cognitive predictors.

= 179, 82 girls, 97 boys). At both time points, children learned the true cause of a light effect and were presented with a false claim about its cause. We assessed children's verbal counterarguments and the generation of physical disconfirming evidence. At 4 years, approximately half of the children demonstrated the ability to provide valid verbal causal counterarguments, which increased to 70% at 5.5 years. Remarkably, at 4 years, 90% of the children selected causally efficacious unconfounded evidence over an ambiguous alternative. Furthermore, developmental progress was observed from 4 to 5.5 years in flexibly utilizing different types of disconfirming evidence. These findings indicate that as early as 4 years old, children exhibit a genuine understanding of falsification through evidence, distinguishing confounded from unconfounded evidence when confronted with a claim they know to be false. The associations with cognitive abilities suggest that development in argumentation from 4 to 5.5 years primarily revolves around the capacity to utilize diverse evidence, related to children's ability to represent multiple higher order rules and perspectives. The potential educational implications for fostering young children's scientific reasoning and argumentation abilities are discussed. (PsycInfo Database Record (c) 2026 APA, all rights reserved).