This chapter investigates the wide spectrum of maladaptive social and communicative behaviors, exploring the underlying neurobiological systems that govern social interaction. The discussion begins by classifying various forms of dysregulated communication, including aphasias, disorganized language, mutism, and prevarication. It then examines social withdrawal by introducing the essential neural networks responsible for social approach, avoidance, affiliation, aversion, mirroring, and mentalizing. A major focus is placed on autism spectrum disorder (ASD), detailing its clinical features, relevant animal models, and specific neural correlates associated with impaired social communication. Finally, the chapter addresses the pathological extremes of social behavior, analyzing the neurocircuitry associated with lack of empathy, excessive interpersonal bonding, and aggression, thereby providing a comprehensive framework for understanding the biological bases of social maladaptation.