The New Zealand historiography on intellectual disability has been expanded in the twenty years by histories of the residential institution and the foundation of advocacy groups. However, there is still a limited field of history regarding how the intellectually disabled were discussed in twentieth century New Zealand. This thesis will discuss how the identity of the intellectually disabled was constructed as a social category, through different discourses, in twentieth century New Zealand. It shall be argued that from 1900 to at least 1960 those who created medical, government and public discourse also maintained the power to create the identity of the intellectually disabled. This argument will take the form of a discourse analysis and will draw on both primary and secondary sources. The primary sources will include government documents, medical literature and newspaper content. The secondary sources will cover material which provides context, and / or which has discussed the construction of intellectual disability. It will be argued that discourses centred on an idea of a 'problem' within the intellectually disabled individual. Also, the medical discourse and 'medicalized' understandings of intellectual disability will be seen to influence public and government discourse. Further, a tension will be shown in these discourses between the desire to assist the intellectually disabled and their families, as well as to protect the New Zealand community from these people