Behavioral correlates to happiness (i.e., indices of happiness) have been used as means of measuring happiness in individuals with developmental disabilities. However, research has not yet evaluated the possibility that indices of happiness/unhappiness (IHUs) may signal the presence of a setting event that could affect other behaviors. The purpose of this study was to assess the relation between indices of happiness/unhappiness (IHUs) and challenging behavior with a 14-year-old boy diagnosed with autism spectrum disorder. A conditional probability calculation was used to evaluate the relation between IHUs, demand type, and challenging behavior. Results indicated that different IHUs predicted specific topographies of challenging behavior given demands to transition or engage in academic tasks.