People act more prosocially when they know they are watched by others, an everyday observation borne out by studies from behavioral economics, social psychology, and cognitive neuroscience. This effect is thought to be mediated by the incentive to improve one's social reputation, a specific and possibly uniquely human motivation that depends on our ability to represent what other people think of us. Here we tested the hypothesis that social reputation effects are selectively impaired in autism, a developmental disorder characterized in part by impairments in reciprocal social interactions but whose underlying cognitive causes remain elusive. When asked to make real charitable donations in the presence or absence of an observer, matched healthy controls donated significantly more in the observer's presence than absence, replicating prior work. By contrast, people with high-functioning autism were not influenced by the presence of an observer at all in this task. However, both groups performed significantly better on a continuous performance task in the presence of an observer, suggesting intact general social facilitation in autism. The results argue that people with autism lack the ability to take into consideration what others think of them and provide further support for specialized neural systems mediating the effects of social reputation.Asperger syndrome | audience effect | dictator game C oncern for our own reputation affects how we behave in social situations. Our actions are strongly influenced by our belief that they may be seen and evaluated by others. Not only do people care about their reputation, but they also often try to manipulate what other people think of them through self-presentation or impression management (1), topics with a long history in social psychology. It is well known that subjects tend to behave in a more egoistic manner under guaranteed anonymity, whereas less anonymous situations increase prosocial behaviors (e.g., giving some benefit to others, adhering to a public standard or to social norms) (2). Prosocial behaviors can be elicited not only by the presence of real observers (3-5) but also by surprisingly subtle cues associated with being watched by others (6, 7), pointing to the powerfully automatic nature of reputationbased processing. Although altruistic behaviors toward nonkin may be present even in nonhuman primates (8), it is likely that only human altruistic behavior is affected by the presence of an independent third party (9). Representing our reputation involves thinking about what others think of us and thus requires some level of metarepresentation (10). The link between prosocial behaviors and reputation is also emphasized by theoretical and empirical considerations of how altruism might have evolved through indirect reciprocity (11,12). Thus, reputation may be a unique and important aspect of our species that incentivizes self-interested individuals to conform to social norms.Autism spectrum disorders (ASD) are a class of neurodevelopmental disorders with an estim...