Background: Very little research thus far has examined the decision making that underlies inappropriate social behavior (ISB) post-TBI (traumatic brain injury). Objectives: To verify the usefulness of a new instrument, the Social Responding Task, for investigating whether, in social decision making, individuals with TBI, who present inappropriate social behavior (ISB), have difficulty anticipating their own feelings of embarrassment and others’ angry reactions following an ISB. Methods: Seven subjects with TBI presenting with inappropriate social behavior (TBI-ISB), 10 presenting with appropriate social behavior (TBI-ASB), and 15 healthy controls were given 12 hypothetical scenarios three times, each time ending with a different behavioral response. Subjects were asked to gauge the likelihood of their displaying the behavior in that situation (part A) and of it being followed by an angry reaction from the other or by feelings of embarrassment in themselves (part B). Results: TBI-ISB subjects scored higher than TBI-ASB and healthy controls on a scale of likelihood of displaying an ISB. Results regarding expectations of angry reactions from others and feelings of embarrassment after an ISB were similar among groups. Negative correlations between endorsement of an inappropriate behavior and anticipation of negative emotional consequences were significant for both TBI-ASB and control subjects, but not for TBI-ISB subjects. Conclusions: Results suggest that the TBI-ISB participants were likely to endorse an ISB despite being able to anticipate a negative emotional response in themselves or others, suggesting that there were other explanations for their poor behavior. A self-reported likely response to hypothetical social scenarios can be a useful approach for studying the neurocognitive processes behind the poor choices of individuals with TBI-ISB, but the task needs further validation studies. A comprehensive discussion follows on the underlying mechanisms affecting social behaviors after a TBI.