This study explores the impact of Peer-Assisted Reflection (PAR), a structured active learning strategy that emphasizes peer feedback and reflection, on students' perceptions of mathematical thinking, and of the roles their peers and their instructors play in their learning process. This study also examines the impact of PAR on the students' ability to evaluate mathematical arguments and communicate those evaluations in writing, which has not been specifically measured in prior research on PAR. The findings suggest that the PAR intervention not only increases students' ability to communicate effectively, but also gives them a newfound recognition of the importance of developing communication skills in mathematics. Additionally, students' thinking about mathematics shifts as they come to value the exploration of multiple perspectives in solving math problems. Many students explicitly note their increased appreciation for the role of their peers in the learning process.