The growing adoption of active learning techniques in physics courses requires that students productively engage in collaboration with their peers. Although studies in physics education research (PER) have addressed aspects of group work, the problem persists of how to engage students in collaborative work with appropriate self-awareness, adequate argumentation skills, openness to the views of others, and willingness to negotiate their ideas. This article presents "intellectual humility" (IH) as a new construct for PER to help advance our understanding and support of students' collaboration with peers. The aim of the work is to formally introduce the construct of IH and to report on the results of a mixed-methods study investigating students' learning experiences in introductory physics courses through an IH lens. The study provides quantitative evidence about how students gauge their own IH based on analysis of survey responses. We find that students report high levels of love of learning, one characteristic of IH, however, the findings also point to students' discomfort with intellectual limitations and inadequate handling of these shortcomings during group work. Results suggest that students would benefit from learning spaces that welcome and encourage discussions around uncertainties, with minimal social risks that may be perceived as hindering their engagement.