A personal psychological issue which affects the individual's probability of suffering the accident. The concept has been studied statistically under the number of different supposition for the accidents:
1)pure chance, leading to the Poisson distribution;
2)true contagion, i.e. the hypothesis that all individuals initially have the same probability
of having an accident, but that this probability changes each time an accident happens;
3)apparent contagion, i.e. the hypothesis that individuals have constant but unequal probabilities of having an accident.
The study of the accident proneness has been very much valuable in the development procedure of particular statistical methodologies, though in the past two decades this concept has, generally, been out of the favour; attention now seems to have moved more towards the risk evaluation and analysis of it as well.