Much research has been undertaken since the 1960s to determine how people make ethical decisions. Business schools around the world have also dedicated increased efforts to ethics education since the late 1980s. However, the research fails to support the effectiveness of this effort in preventing or reducing unethical outcomes in business. The majority of existing business ethics research makes two fundamental assumptions: firstly, that 'bad' people do 'bad' things owing to: a lack of character; bad values; or greed; and, secondly, that ethical decision making is a rational, cognitive process that can be taught.In this thesis emerging research in the fields of criminology, social psychology and neuro-cognitive science is built on, questioning these two assumptions. It is shown that ethical decision making is most often a subconscious process with higher order reasoning not engaged until after the event. It is also shown that in trying to understand our own and others' behaviour, we overestimate the importance of dispositional qualities and under estimate the importance of situational and systemic factors.Research indicates the key factors in unethical behaviour to be: self-delusion; perceptual biases; and ethical blindness linked to learned justifications that neutralise moral intent. Therefore, the aim of this thesis is to understand why people of good character and without ill intent create unethical outcomes in business and how moral intention, perceptual blindness and moral neutralisations interact and impact upon this social psychology and neuro-cognitive science. The aim is to develop a model that shows how, in theory, ethical outcomes are created. Drawing on a social constructivist paradigm a multiple case study research design utilising qualitative data is determined to be the most appropriate method to test this theoretical model. Participants in the research were drawn from people at Board or senior executive levels who had either been charged with corporate crimes or who had been a whistle-blower in such crimes.Semi-structured interviews were conducted with the aim of encouraging participants to reflect on and describe the phenomenon they had experienced. The theoretical model was used as a starting point for these interviews to explore the events from the subjects' perspective. These interviews were then supplemented and triangulated by an analysis of corporate documents, media reports and, where possible, court reports.The data gathered from the research was then coded and analysed for patterns to enable