'Deep implications' or 'an oversimplified approach'?-Gibson's ideas 50 years on

There have been few individuals in the field of perception whose ideas have provoked as much controversy and heated argument as J. J. Gibson. On the one hand, one writer sympathetic to his ideas has claimed: 'Whatever the final status of Gibson's theories, his work has significantly changed the scientific study of human awareness and has deep implications for anyone interested in human behaviour and knowledge' (Reed, 1988) while one of his critics asserted: 'He [Gibson] did for perception what Skinner did for animal learning: he handicapped a generation of workers by his blinkered and oversimplified approach' (Sutherland, 1991). Given this background, how should we evaluate Gibson's British Journal of Psychology paper, written exactly fifty years ago? This question can be answered best by seeing the paper in the context of the development of Gibson's ideas. In 1947, Gibson wrote a lengthy account of his research on pilot selection and training during Second World War in which he argued that the traditional view of depth perception based on binocular disparity was not particularly relevant for the training of pilots and, more importantly, should not be regarded as the primary basis for depth perception in general (Gibson, 1947). As evidence, Gibson cited the example of Wiley Post -- a very successful pilot despite being blind in one eye -- and the striking appearance of depth that can be seen in a single photograph when the cues to the flatness of the picture are minimized. In contrast, Gibson argued that the continuous surface of the textured ground plane that creates gradients of size, and retinal motion when we move, provide a richer and more reliable basis for judging distance and space. At that time, the twin ideas of the optic flow created by an observer's movement through the world and the gradients of texture created by surfaces in the environment were both novel. Of course, Helmholtz (1909) had written about the cues of motion parallax and relative size but Gibson claimed that optic flow and texture gradients were not mere additions to the well-established list of depth cues but instead they formed the basis of an alternative 'ground theory' of space perception. Adapted from the source document.