We study cognitive development, with a primary focus on how children think, learn, and solve problems in mathematics. The development of mathematical thinking presents a paradox. On one hand, young children (and possibly even infants) have been shown to exhibit a fairly sophisticated understanding of fundamental math concepts. On the other hand, math is a notoriously difficult subject to learn in school, with many children (and adults) failing to achieve basic competence. In our studies, we investigate cognitive processes that contribute to people's understanding (and misunderstanding) of math. Through this work, we seek to uncover mechanisms involved in the development of quantitative reasoning, symbolic understanding, and problem solving. Our research has practical implications. For instance, it may help parents and teachers determine the best ways to structure the environment, so all children can be provided with the building blocks necessary for success in school and beyond. Our research is funded by Institute of Education Sciences and National Science Foundation.


The math intervention Prof. McNeil and her research team have developed was featured in a "What Would You Fight For?" Commercial on NBC. This intervention is designed to improve children's understanding of mathematical equivalence, a fundamental concept in math. To learn more about the intervention, please read this summary. To learn more about the school featured in the commercial, please visit the Notre Dame ACE Academies website. The efficacy of the intervention is currently being tested with the help of WestEd.