I was chatting to a lawyer recently about advances in environmental standards when he came up with the inevitable negative anecdote that people often advance in resistance to change, particularly the application of higher standards which will involve them putting their reluctant hands into their pockets to invest in something that is imposed upon them. Or, for example, having to modify their behaviour with the inevitable loss of some privilege or pleasure. Examples would be; speeding behaviour on the roads, smoking, environmental improvements of various kinds. Often these changes will have their benefits at a societal scale by reducing mortality or morbidity but are unlikely to have any specific benefit for individuals. This, of course, being the outworking of chance in populations subject to environmental stressors.
The typical negative assertion that is brought into the argument is something along the lines of “I’ve been doing X for forty years and I’ve never been ill” or “I know lots of people who’ve been doing X all their lives and they’re now eighty”. The second case, of course, describes the survivors, not the ones who have fallen by the wayside through the years, been buried and forgotten.
It is the first argument, the negative assertion, that I wish to address. The principle here is that a negative assertion is not evidence, it is merely prejudice. Evidence in terms of environmental stressors acting on populations comes from epidemiological research, not the collection and reporting of anecdotes. Anecdotes have value in that they express the societal myths about particular issues and therefore evidence the need for considering cultural expectations and honestly-held opinions in managing and promoting change. They do not, however, provide an objective truth about the relationship between a stressor or environmental agent and the morbidity or mortality that could arise in a population as a consequence.
So, why the use of the term prejudice? Prejudice simply means to form a judgement in advance of the facts of the case. My negative experience of one cap-wearing driver of a white Ford Escort is anecdotal of that incident, not predictive of the behaviour of other cap-wearing drivers of white Ford Escorts nor the consequences of meeting them on the road. Were I to consider that all cap-wearing drivers of white Ford Escorts were likely to behave in an unpredictable or dangerous manner on the road, I would be expressing a prejudice.
But there is a second form of prejudice expressed here, which is the one I wish to consider in the context of the negative assertion. That is the prejudice that assumes the unwilling individual is going to have to change their behaviour, or spend money they don’t wish to, without a perceived personal benefit that would outweigh the cost of participation in the change process. And herein lies the rub; benefits arising from reducing environmental stressors or exposure to pollutants generally arise to the population as a whole in terms of better health and life expectancy, they very seldom deliver a tangible and welcome benefit for any random individual.
Perhaps the aphorism should be re-written thus: a negative assertion is not evidence, it is merely the expression of a resistance to change. Less snappy, for sure, but less liable to misinterpretation.