CHILD DEVELOPMENT PERSPECTIVES Moral Judgment and Moral Neuroscience: Intersections, Definitions, and Issues Melanie Killen 1 and Judith Smetana 2 1 University of Maryland and 2 University of Rochester ABSTRACT—The moral neurosciences are an emerging area of research that has the potential to improve our understanding of the biological basis of morality. Thus far, however, research on moral neuroscience and moral judgment development has proceeded independently and with little interconnection. The current article discusses how morality has been defined and assessed in several new and prominent lines of research in the moral neuro- sciences and in research over the past 30 years on moral judgment development. It discusses how the 2 lines of research could be better integrated and points to strengths and limitations in the current field. Finally, suggestions are provided for further research. KEYWORDS—morality; moral judgment; moral neurosci- ence; moral development; empathy The moral neurosciences are an emerging area of research that has the potential to improve our understanding of human social and moral behavior. The field reflects a multidisciplinary approach that integrates theory and research in philosophy, psychology, economics, and neuroscience. Although recent reports have forged new ground, ambiguities have also arisen about the meaning of the findings, particularly as different areas of scholarship define and measure morality differently. Scholars have theorized about morality as an aspect of human nature since antiquity (see Aristotle), primarily debating whether morality centers on reason and rationality (Kant, 1785/1959) or emotions and affect (Hume, 1739/1969). Thus, to some extent, the diversity of definitions is not surprising. The empirical research on moral judgment development and decision making has drawn on philosophical definitions, rooted in Kantian theories of ethics (Kohlberg, 1971; Piaget, 1932; Turiel, 1983) and, more recently, using neo-Kantian criteria for moral judgment (Gewirth, 1978). In addition, Humean theories of affect, centering theories on shame, guilt, and empathy, have been reflected in research on prosocial behavior (Eisenberg & Fabes, 1998; Eisenberg, Spinard, & Sadovsky, 2006; Hastings, Zahn-Waxler, & McShane, 2006). In the past 30 years, a wealth of empirical studies have examined children’s moral develop- ment, as reviewed in a recent handbook on moral development (Killen & Smetana, 2006). Moral neuroscience research often addresses issues related to current and ‘‘hot’’ points of discussion in psychological science, such as differences between moral reasoning and moral intui- tionism, cognition and emotion, or implicit and explicit forms of judgment. This research has documented the areas of the brain that are activated when individuals solve moral dilemmas, experience social exclusion, make judgments about moral character, respond to a problem involving empathy, and make decisions involving trust (Blair & Cipolotti, 2000; Delgado, Frank, & Phelps, 2005; Greene, Sommerville, Nystrom, Darley, & Cohen, 2001; Hauser, 2006; Marshall & Fox, 2006). These analyses of the biological underpinnings of morality bear on and could enrich the work of developmental scientists investigating the emergence of moral judgments. At the same time, we believe that advances in moral developmental research are missing from the current neurosci- ence research and that an integrated approach could be mutually beneficial. In this essay, we focus primarily on moral judgment rather than moral emotion. Although researchers studying moral judgment development typically consider the role of moral emotions, and particularly empathy, the two constitute a substantial area of research with a unique set of The first author would like to thank the social neuroscience reading group at the University of Maryland for helpful discussions about morality and neuroscience, and both the authors would like to thank Noah Simon Jampol for his assistance with the literature review. Correspondence concerning this article should be addressed to Melanie Killen, Department of Human Development, 3304 Benjamin Building, University of Maryland, College Park, MD 20742-1131; e-mail: mkillen@umd.edu or Judith Smetana at smetana@psych.rochester.edu. # 2008, Copyright the Author(s) Journal compilation # 2008, Society for Research in Child Development Volume 2, Number 1, Pages 1–6