Children and adult learners benefit from viewing hand gestures at instruction across domains (Cook, Duffy, & Fenn, 2013; Huang, Kim, & Christianson, 2019; Ping & Goldin-Meadow, 2008). Within the domain of mathematical learning, gesture at instruction has been shown to benefit children and adults in laboratory and classroom settings (Koumoutsakis, Church, Alibali, Singer, & Ayman-Nolley, 2016; Rueckert, Church, Avila, & Trejo, 2017). While gesture is shown to benefit learning, the underlying mechanism by which gesture enhances learning is unknown and, it is unclear to what extent the beneficial effects of gesture generalize. In three experiments, we sought to understand who gesture is most helpful for, whether gesture is more beneficial with less instruction, and what presentation gesture helps with. First, we examined whether individual differences in working memory capacity related to mathematical learning in an enhanced mathematical task, as we aimed to replicate our prior work suggesting visuospatial working memory capacity is specifically important in processing gesture at instruction (Experiment 1). Second, we examined whether the amount of instruction interacts with the presence of gesture (Experiment 2). And third, we examined whether the presentation style of the same mathematical concept interacted with the presence of gesture to explore whether gesture specifically benefits learning when concepts are presented in certain formats (Experiment 3). We found visuospatial working memory to be a reliable predictor of performance, regardless of whether gesture was present or absent at instruction (Experiment 1), we found gesture to not reliably enhance mathematical learning, regardless of how much instruction was provided with or without gesture (Experiment 2), and we found gesture to predict learning when a mathematical concept was presented in a visuospatial format, but not when the same concept was presented in an algebraic format (Experiment 3). Altogether, our results suggest that the beneficial effect of gesture on learning depends more on characteristics of a lesson than previously believed, and that gesture at instruction may not always benefit adult learners. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]