In Brief

  • Many safety rules related to driving exist and are accepted without critical evaluation.

  • When examined, many of these safety heuristics are predicated on what appears to be common sense or tribal wisdom, but actually conflict with existing scientific and technical research.

  • The prudent safety professional must look at the underlying research to determine whether available scientific data supports or refutes the rules before relying on them, even if those rules may have been codified into law or official policy.

  • Official bodies' adoption of incorrect information does not improve the quality of that information; tribal wisdom should never be confused with empirical fact.

The public looks to safety professionals for guidance as experts in risk avoidance and hazard mitigation. This is reasonable as they are ostensibly trained in that area and, thus, in a better position to evaluate the risks inherent in different activities and to assess what can and should be done to alleviate or reduce those risks to an acceptable level. As such, it behooves safety professionals to be aware of not only safety-related heuristics that are presented to the public, but also the research that underlies that guidance to assess the appropriateness of the various safety rules that are promulgated to address potential hazards. In the real world, however, ostensible safety experts often simply accept these rules as representing appropriate, normal or typical behavior based on longevity, common sense or the simple frequency with which they are expressed.

One example of this (with which most parents are likely familiar) is the "5-second rule": the idea that food dropped onto the floor and quickly retrieved is still safe enough to eat. The rationale seems to be that bacteria requires a longer time to transfer from the floor surface to the food. In a study by researchers at Rutgers University involving multiple foods, surfaces and contact durations over 2,500 measurements, it was discovered that, while longer contact times result in more bacteria transfer, other factors (e.g., nature of the food, surface onto which it is dropped) are of equal or greater importance (Miranda & Schaffner, 2016). The study concluded that bacteria were found to instantaneously contaminate the dropped food, debunking the idea that eating food quickly retrieved from the floor was safe.

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