It has long been established that interpersonal relationships can have a profound impact on health and well-being. Yet, we are still learning about the complex biological processes that contribute to positive social interactions and the ability to develop and maintain social relationships. Recent research has begun to focus on oxytocin and vasopressin, neuropeptides that are naturally produced in the hypothalamus, because administration of these neuropeptides has been associated with increased trust, generosity, empathy, cooperation, memory of social stimuli (e.g., faces), and brain activity in neural regions associated with social and emotional processes. To date, several aspects of oxytocin and vasopressin's effects on social behavior have been unexplored. As such, the overarching goal of this project is to examine the effects of intranasal oxytocin and vasopressin on social working memory, deception detection, sensitivity to interpersonal distance, empathy, and altruistic behavior. Understanding how oxytocin and vasopressin influence these aspects of social functioning will help to inform research that has begun to establish the potential for use of these neuropeptides in psychiatric disorders such as autism spectrum disorders and schizophrenia that are characterized by social deficits. For this study, we will recruit 150 healthy adults without a history of medical or psychiatric illness to come to the laboratory. In the first session, participants will complete several questionnaires. In the second session, participants will be randomly assigned to receive oxytocin, vasopressin, or placebo. The study nurses will measure temperature, heart rate, and blood pressure (female participants will also be asked to undergo a pregnancy test) before drug administration. Participants will then complete computer tasks. During the second session, we will also collect a saliva sample for genetic analysis and participants will be asked to complete several additional questionnaires. At the end of the experimental session, participants will be fully debriefed. The investigators hypothesize that compared to placebo, oxytocin and/or vasopressin will improve social working memory and deception detection, and increase empathy and altruism. It is also hypothesized that main effects will not be found for oxytocin or vasopressin, but rather, analyses of relevant moderators will elucidate these findings.