Hear What They Say and Watch What They Do - Predicting Valid Mathematical Proofs Using Speech and Gesture.

In mathematics, practices of proof are notoriously difficult for learners to adopt. In prior work, we found that when providing verbal justifications, learners’ speech patterns predict whether their justifications are mathematically sound. However, current views on the embodied nature of cognition suggest that actions and speech may co-constitute reasoning processes. The current study investigated whether the gestures learners use while formulating proofs also predict proof validity. 120 undergraduates provided verbal justifications for two mathematical tasks. We analyzed speech patterns in participants’ justifications using text analysis software, and we coded participants’ gestures as dynamic or static. Results showed that dynamic gestures were correlated with mathematically valid proofs and with specific patterns of speech. A stepwise logistic regression model found that speech and gesture separately account for unique variance in a model predicting proof validity, indicating that gesture contributes to mathematical reasoning in an abstract task domain.