Despite initiatives to support women in STEM, men still outnumber women in math-intensive fields, and women in mathematics express that they are "on the outside looking in." Prior mathematics anxiety research has investigated links to performance, and neuroscientists, psychologists, and educational researchers have found gender differences in mathematics anxiety. Past research has identified gendered patterns in classroom compliance, competitiveness, and mathematical confidence. This study examines if and how socialized factors might contribute to gender differences in mathematics anxiety. This research uses an inclusive view of gender, reporting results for sex assigned at birth, gender identity, and gender expression, and recognizing that psychological, social, and biological variables might influence a person's experiences. While prior studies have often ignored or removed transgender and gender nonconforming persons, their viewpoints are included throughout this study. A series of linear regressions (n=84) showed students who tended to be "teacher pleasers" were more likely to have mathematics anxiety, while students who were more contentious and/or mathematically confident were less likely to have mathematics anxiety; sex- and gender-related patterns in mathematics anxiety were no longer significant after the inclusion of these variables in the models. The regressions for both sex assigned at birth and gender identity showed teacher pleasing (p<0.01), contentiousness (p<0.10), and confidence (p<0.001) were significant predictors for mathematics anxiety, with R. 2 increasing from 0.07 to 0.40 and from 0.10 to 0.45, respectively. Similarly, the sets of regressions starting with gender expression, showed teacher pleasing (p<0.01) and confidence (p<0.001) were significant predictors, with R. 2 increasing from 0.08 to 0.31. Semi-structured interviews with 10 focus students explored experiences related to mathematics anxiety and addressed gendered patterns in compliance, competitiveness, and confidence. Girls were said to be hard workers who were "scared" to speak up in class and memorized procedures, and boys were said to loudly boast about grades or little time spent on assignments. Recommendations for teachers are discussed, like de-emphasizing memorization and cultivating a positive classroom culture. Implications for research include incorporating a nuanced view of gender, developing a mathematical competitiveness construct, researching cognitive disruptions of memorized procedures, and investigating peers' influence on confidence and the "socialized silencing" of girls. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]