ABSTRACT
Individual differences in arithmetic are easier to detect in children, who are attending school and taking mathematics tests, but it is clear that they persist throughout life. Some adults have severe difficulties with basic numeracy, and most such adults were already struggling with arithmetic by the age of 7. Personal communications from several male and female mathematicians suggest that one important factor in mathematical research, to a greater extent than for other academic subjects, is the ability to concentrate single-mindedly on a given problem. Further evidence for some genetic component to mathematical difficulties comes from a study of siblings of children with mathematical disabilities. Spatial ability has frequently been suggested to be an important factor in mathematical performance in general, and in gender differences in mathematics in particular. If arithmetic is indeed influenced by gender differences in spatial ability, the influence is likely to be quite limited and subtle.
