Towers of Hanoi and London: Reliability and Validity of Two Executive Function Tasks.

The Towers of Hanoi and London are presumed to measure executive functions such as planning and working memory. Both have been used as a putative assessment of frontal lobe function. In this study, both tasks were administered to 61 normal adult participants to test the assumption that the two tasks are measuring the same cognitive processes. The results revealed a significant, but relatively low (.37) correlation between performances on the two tasks. Follow-up analyses indicated that the likely source of the lack of convergence was the unreliability of the Tower of London. Thus, the common assumption that the two tasks are isomorphic must be questioned.