Many youth with autism spectrum disorder (ASD) experience increased daily stress due to ASD-related symptoms. Social skills challenges, communication difficulties, or sensory sensitivities could potentially generate stress for youth with ASD in a variety of contexts. In typically developing children, stress level can be measured using a variety of techniques, such as collection of saliva samples (i.e., salivary cortisol collection). This technique is reliable and noninvasive. In this study, we plan to use salivary cortisol collection and examine the relation between cortisol and stress in youth (age 7-14) with high-functioning autism or Asperger's Syndrome. Establishing a relation between cortisol and stress in youth with ASD has the potential to serve as an objective marker of distress in youth who often have difficulty reporting emotions. Further, it will provide a more complete understanding of the physiological systems underlying stress and anxiety in ASD. This project is supported in part by a UCLA Center for Autism Research and Treatment (CART) Pilot Grant award to Lindsey Sterling, Ph.D. who works with CART investigator Jeffrey Wood, Ph.D.