Joint British Academy/British Psychological Society Lecture, delivered by Professor Brian Butterworth FBA, on 16 November 2004.
Poor numeracy is a serious educational and social problem. It is more of a handicap in employment than poor literacy. One of the most important causes of poor numeracy is dyscalculia, a selective congenital disability for arithmetic. Although the current best estimates put its prevalence at more than 5%, more than dyslexia, few parents, teachers, or government bodies recognise it, as they failed to recognise dyslexia thirty years ago. However, recent research has discovered that the dyscalculic’s painful struggle to acquire basic arithmetical facts and procedures seems to be due to a pathologically weak grasp of basic number concepts, despite normal intelligence, memory and language. This can be detected even in simple tasks that come easily to most of us, such as estimating small numbers of objects and comparing numbers. The brain systems underlying these tasks have now been identified, and there is evidence suggesting that these systems are abnormal in dyscalculics.