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Idiot savant calendrical calculators: rules and regularities

Published online by Cambridge University Press:  09 July 2009

B. Hermelin*
MRC Developmental Psychology Project, Institute of Education, London
N. O'Connor
MRC Developmental Psychology Project, Institute of Education, London
1Address for correspondence: Dr B. Hermelin, MRC Developmental Psychology Project, Institute of Education, 18 Woburn Square, London WC1H 0NS.


The three experiments described aimed to establish whether the achievements of idiot savant calendrical calculators were based solely on rote memory and arithmetical procedures, or whether these subjects also used rule-based strategies. It was found that, although different structural calendar regularities were tested by using differing experimental paradigms, all subjects could at least use some of the rules under investigation. The more cognitively able subjects could make use of all the three structural regularities of the calendar tested here. It was concluded that idiot savant calendrical calculators can use rule-based strategies to aid them in the calculation of the days on which past and future dates fall.

Research Article
Copyright © Cambridge University Press 1986

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