The goal of this research study is to learn about experiences with repetitive behaviors from autistic teens and their families. In order to learn about your experiences with repetitive behaviors, you will be invited to complete a set of online questionnaires about your (or your teen's) experiences. The goal of this study is to promote advocacy and transparency for autistic teens' lived experiences. A small subset of teens may also be asked to complete a brain MRI and additional behavioral assessments, if they are interested. Participating in the MRI and further behavioral assessments is voluntary and is not required to complete the online surveys.