This study was conducted in a Modeling Instruction Introductory Physics I course and investigates whether students' social interdependence is associated to semester-long conceptual and physics identity gains. In Modeling Instruction, students spend the majority of class time working in small groups leading to varying levels of task and outcome interdependence with other group members. Detailed data were collected to measure pre- to post- conceptual learning and identity gains as well as reported task and outcome interdependence for each student. Students' pre-semester individualism and cooperation beliefs were also collected as these measures have been shown to be correlated with social interdependence. Linear regressions were conducted to understand associations between interdependence measures and pre-to-post semester differences in students' conceptual and physics identity measures; notably, students who reported greater levels of initiated task interdependence also had more positive improvements in their beliefs in being recognized as a physics person. A significant positive shift in student's pre-to-post semester cooperation beliefs was also observed.