Intelligence and individual differences in performance on three types of visually presented optimisation problems

Although problem solving is an essential expression of intelligence, both experimental and differential psychology have neglected an important class of problems, for which it is difficult or impossible for systematic procedures to provide a definitive solution. Two experiments are described, in which participants’ solutions to three computationally difficult problems (a Travelling Salesperson, a Minimal Spanning Tree, and a Generalised Steiner Tree problem) all showed consistent individual differences that intercorrelated reliably and correlated moderately with scores on Ravenʹs Advanced Progressive Matrices. The results are interpreted in terms of a theory of visual perception based on the efficient use of information about the relative position of stimulus elements.