The Visual Implications of Inspection Time

Abstract

The quest to define human intelligence has led researchers down a large range of paths. One such path has been the search for a single, basic psychometric measure that can be used to account for a large portion of the variance in human mental ability. Inspection Time (IT) has emerged at the forefront of these efforts and can be shown to account for approximately 25% of the variance in psychometric tests of intelligence (e.g., IQ). In this study, we attempt to gain an insight into the nature of IT as a psychometric measure by first contrasting individuals that are adept at performing the IT task (those with low ITs) with individuals that are not (those with high ITs) using oculomotor and task-performance measures recorded during two visual tasks. The results of the first experiment show that the current prevailing theory regarding IT, the integration theory, is incapable of accounting for the results found during the visual tasks. This leads us to introduce a novel theory of IT, the watered-tree theory, which places IT as a measure of information propagation. We then perform a second experiment to test the opposing predictions of the integration theory and the watered-tree theory and find that the results are in line with the predictions of the watered-tree theory. A discussion is presented on the implications of the proposed theory and the need for its future validation.