Investigating the psychological foundations of moral judgment

Is there an early developing neuro-cognitive structure that is specific to our moral sense? Recent research has begun to explore this question using a classic thought experiment known as the trolley problem. These “trolley studies” have uncovered what appears to be a universal pattern of moral intuitions in adults that some argue can only be explained by assuming implicit knowledge of complex moral principles. In this dissertation, I build on this work by testing preschoolers’ and adults’ tacit knowledge of the principle of double effect – a principle that has a long history within the fields of philosophy, religion, and law, and which has recently been proposed to underlie our moral intuitions in the trolley problem. I also investigate the role of perceived ingroup/outgroup structure in moral judgment – a factor which others have hypothesized to be a foundation of moral judgment. Across three studies, preschoolers (studies 1 and 2) and adults (study 3) were tested on a series of dilemmas that were similar in structure to the traditional trolley problems, but involved property violations and assault (i.e. the apprehension of bodily harm) rather than “personal” violations such as battery or homicide. In all three studies, participants showed a strong and stable pattern of intuitions consistent with the principle of double effect: dilemmas in which an individual was harmed as a foreseen side effect of saving five people were judged favorably, but dilemmas in which an individual was intentionally harmed as a means to saving five people were judged unfavorably. Four-year-olds and adults (but not three-year-olds) also disapproved of scenarios in which an agent knowingly allowed a preventable harm to occur. Manipulations of minimal ingroup/outgroup structure had little to no effect on either preschoolers’ or adults’ moral judgments in these dilemmas. Implications for the structure and development of moral judgment are discussed.Ph. D.Includes bibliographical referencesby Katharine Saunder