The Theory of the Social Threshold: The Social Aspect of Accident Causation

Abstract

The majority of accidents are the result of factors which, as yet, cannot be tested for. Therefore, for large scale accident reduction we must make not only tests for accident proneness, but examine the environment where proneness which cannot be tested for can express itself. A survey of American figures demonstrates that the sustaining of many accidents in one period is not certainly prognostic of a high accident rate for the same individuals in a future period. There is regression towards the average, a spontaneous improvement (viewed statistically) over a considerable lapse of time. By further analysis it has been shown that accidents cannot be reduced beyond a certain limit by working on individuals who, over a brief period, have had a high accident rate.

The factors contributory to accident causation of all kinds are divided into three groups: intrinsic (individual), extrinsic (social), and natural, and since certain of these factors, especially social, are variable, the accident situation is dynamic not static. Accident proneness is constantly altering as the social environment changes. Following Farmer and Davis, it is concluded that social stresses give rise to emotional changes which in turn disorganise skilled activity.

This effect of social stresses can be resisted by social conditioning, but beyond a certain level or field of social conditioning, here called the social threshold, it is believed the individual becomes accident prone. It is recognised that there is a distinction between individuals who have intrinsic accident proneness detectable by battery testing, and those who are not thus detectable but, in certain environments, have a tendency to accidents. There are also those who show a history of accidents. It is proposed that these groups be called respectively accident prone, accident potential, and accident liable. The dynamic character of the accident situation explains the phenomenon of regression towards the average.