Moral conduct and social behavior

Over the past 150 years, the frontal lobes (FLs) have been implicated in the neural mediation of both normal and abnormal moral conduct and social behavior (MCSB). Despite the remarkable advances that have permeated this period up to the present, a comprehensive account of the neural underpinnings of MCSB has stubbornly defied the best minds of psychology, psychiatry, and neurology. The goal of this chapter is to review a few practical and conceptual achievements that have proved heuristically valuable as an impetus for further advance of knowledge. In virtually all cases in which MCSB was compromised by brain damage, the injuries were located (i) in the prefrontal cortices, (ii) in their connections with the temporal poles and anterior insula, or (iii) in related subcortical structures and pathways, such as the thalamic dorsomedial nucleus or the anterior thalamic radiation. The clinicoanatomic associations among these structures originated the "frontal network systems" concept, which satisfactorily explains the occurrence of classical FL syndromes in patients with lesions outside the prefrontal cortices. Overall, clinicoanatomic observational studies and experimental evidence from patients with acquired sociopathy/psychopathy indicate that abnormalities of MCSB are the final common pathway of single or mixed impairments of subordinate psychologic and neural domains that support MCSB. Independent studies on normal volunteers concur with this view, indicating that MCSB is shaped by the dynamic interplay of subordinate psychologic domains, such as moral sensitivity and judgment, and their neural correlates.