To be human entails an awareness of the ideal, of what ‘ought to be’, and an ability to compare it with actual states. An awareness of this gap influences many aspects of human life, including a sense of humour, hopes for the future and a sense of guilt or shame. However, perceptions of reality are potentially distorted by cultural and psychological factors, such as false memories. Anthropological perceptions of other cultures can also be distorted by attempts to categorize cultures according to theoretical categories which filter the data through interpretive frameworks.