Researchers from Durham University believe that children who under-achieve at school may not be doing so because of low intelligence, but rather because they have a poor working memory. Their survey of 3000 primary school children suggested that as many as 10% of children have difficulties in this area - the condition is thought to be genetic, and impacts on areas such as holding information in your head.
The latest paper from the Durham team does not appear to be online, but you can read some of the previous research that they have done in this area. Listed below are two references to journal articles which they have authored; both of them can be found in hard copy in Summer Row Library, or are also available via the Blackwell-Synergy service in Athens.
Alloway, T.P., Gathercole, S.E. & Pickering, S.J. (2006) Verbal and Visuospatial short-term and working memory in children: Are they separable? Child Development. Vol. 77, No. 6, pp. 1698-1716.
Gathercole, S.E & Alloway, T.P. (2006) Short-term and working memory impairments in neurodevelopmental disorders: diagnosis and remedial support. Journal of Child Psychology and Psychiatry. Vol. 47, No. 1, pp. 4–15.