Morals and the human brain: a working model.

Morality has been at the center of informal talks and metaphysical discussions since the beginning of history. Recently, converging lines of evidence from evolutionary biology, neuroscience and experimental psychology have shown that morality is grounded in the brain. This article reviews the main lines of investigation indicating that moral behavior is a product of evolutionary pressures that shaped the neurobehavioral processes related to the selective perception of social cues, the experience of moral emotions and the adaptation of behavioral responses to the social milieu. These processes draw upon specific cortical-subcortical loops that organize social cognition, emotion and motivation into uniquely human forms of experience and behavior. We put forth a model of brain-behavior relationships underlying moral reasoning and emotion that accommodates the impairments of moral behavior observed in neuropsychiatric disorders. This model provides a framework for empirical testing with current methods of neurobehavioral analysis.