Abstract
Interest in ethical issues has increased after the Second World War. Two events that influenced this were the research that took place in the concentration camps and the Manhattan Project, in which the atomic bomb was developed. Different ethical starting points in connection with different opinions about research work, methods and procedures give, however, a wide perspective of the field. A normative approach is often mixed with a descriptive approach. The main reasons for highlighting ethical issues in research are to protect people who participate in research in different ways, and to avoid negative consequences for the participant. In research on persons with intellectual disability ethical considerations are extremely important as many of these persons have difficulties in communication and in speaking for themselves.