This study funds a PhD student to analyse unique data previously collected on a cohort of several thousand twins relating to cognition. Cognitive data was obtained using an interactive computer program, CANTAB which assessed areas in working memory and processing speed. A measure of IQ, using the National Adult Reading Test, was also collected. A short memory questionnaire was administered in 2000, 2002 and as a supplement to a 16 item prospective and retrospective memory questionnaire in 2004. The study aims to find out to what extent genes are responsible for cognitive functioning and everyday memory slips. Then, it is hoped to link specific aspects of these behavioral traits to the genes that may be involved.