Profiling cognitive biases in primary school children’s plane geometry: A dual-process study of prototype and area-perimeter reasoning

Source abstract

Early geometric reasoning predicts later mathematical achievement, yet children’s errors in this domain persist across instruction and are conventionally labelled “misconceptions.” Dual-process theory offers an alternative reading, that many such errors are cognitive biases, in which a fast intuitive response overrides slower analytical reasoning, but this framework has been applied mainly to numerical tasks and to adolescents or adults, leaving elementary geometry largely unexamined. It therefore remains unclear whether children’s geometric errors reflect genuine intuitive interference or a simple lack of knowledge. This study profiles cognitive biases in the plane-geometry reasoning of elementary school students, focusing on prototype-based shape recognition and area-perimeter comparison, and uses a congruent-incongruent task design to separate intuitive interference from missing knowledge. Employing a qualitative descriptive design, fourth- and fifth-graders at a high-performing school in South Sulawesi completed task-based clinical interviews combining congruent and incongruent items with think-aloud and probing; episodes (one student × one item) were analyzed thematically for bias forms, sign patterns, and inhibition markers. Prototype bias appeared in 13 of 15 students—most often as orientation-based rejection—and area-perimeter bias in 12, most often as the “larger perimeter, larger area” rule. Crucially, the dominant pattern was accuracy on congruent but not incongruent items, and most such errors were accompanied by self-correction, indicating failed inhibition of available knowledge rather than absent knowledge. The study extends the dual-process framework to spatial-geometric reasoning in early childhood and reframes many geometric “misconceptions” as inhibitable cognitive biases, implying that diagnosis should precede remediation.