Individual differences in cognitive planning on the Tower of Hanoi task: Neuropsychological maturity or measurement error?

The Tower of Hanoi (ToH) task was given to 238 children aged from 7 to 15 y ears, and 20 adults. Individual variation within an age band was substantia l. ToH score did not correlate significantly with Verbal IQ, nor with abili ty to inhibit a prepotent response. We readministered the ToH to 45 childre n after 30 to 40 days. The test-retest correlation of .5 is low in relation to accepted psychometric standards, though at least as high as reliability of the related Tower of London (ToL) in adults. The reasons fur low reliab ility remain unclear; task novelty did not seem to be involved, as children did not improve on retest. We conclude that it is not safe to use this tes t to index integrity or maturation of underlying neurological systems in ch ildren. We compared our results with three published studies using the Tot with children, and found similar levels of performance on problems involvin g the same number of moves. Another study using automated Tot obtained much poorer scores. suggesting that computerised presentation may impair childr en's performance.