The neurobiology of moral sense: facts or hypotheses?

One of the most intriguing frontiers of current neuroscientific research is represented by the investigation of the possible neural substrates of morality. The assumption is that in humans an innate moral sense would exist. If this is true, with no doubt it should be regulated by specific brain mechanisms selected over the course of evolution, as they would promote our species’ survival. In the last decade, an increasing number of studies have been carried out to explore the neural bases of human morality. The aim of this paper is to present a comprehensive review of the data regarding the neurobiological origin of the moral sense, through a Medline search of English-language articles from 1980 to February 2012. The available findings would suggest that there might be a main integrative centre for the innate morality, in particular the ventromedial prefrontal cortex, with its multiple connections with the limbic lobe, thalamus and brainstem. The subjective moral sense would be the result of an integration of multiple automatic responses, mainly associated with social emotions and interpretation of others’ behaviours and intentions. Since converging observations outline how lesions of the proposed neural networks may underlie some personality changes and criminal behaviours, the implications of the studies in this field encompass many areas of the scientific domain.