What Is Normal – Can Normative Data Ever Exist In A World Of Individual Differences And Qualia

In the last few days I attended a wonderful conference in Dullstroom near the Kruger National Park in South Africa on rural doctors training, and the point was made that what was ‘normal’ training in the medical school environment would not work when planning to set up training sites for doctors in rural areas. I read a recent Twitter debate which once again discussed whether it was normal for humans to eat carbohydrates or fats, and whether our predecessors had done so in ancient / prehistoric times. Most importantly, I was reminded by Professor Mike Lambert of the University of Cape Town, my old PhD supervisor, mentor and good friend (and scientist whom I most admire) of one of the most brilliant philosophy of science articles, written by Johan Koeslag in the early 1990’s, where he examined the question of ‘what is normal’ and how we define normality. All these got me thinking of how science and medicine differentiates normality from abnormality, and how we as a society often ‘brand’ folk as abnormal based on our own world-view and social or clinical paradigms, and by doing so potentially stigmatize those that we label as abnormal.

Johan was a Physiology Professor at the University of Cape Town in the 1980’s who had a profound effect on my way of thinking (and surely a lot of other folk) during my medical and PhD training, by always making us question dogma and routine thinking in science, medicine and society, in a firm but uncondescending way. He published a number of incredibly thought provoking philosophical articles throughout his career, and while all were great, to me perhaps his best was his article on normality and how it is defined. The definition of ‘normal’ is to conform to a standard, to be usual or typical. Johan suggested that the categorisation of biological phenomena as normal or abnormal was the absolute basis of medical practice, and that without defining individuals such there could be no medical or health services. He perceived that medicine and science used the concept of normality to define at least five independent, and potentially mutually contradictory, states, namely i) not ill; ii) the best; iii) operating as intended; iv) conforming to a cultural norm; or v) the usual. But, as he described, each of these definitions or ‘states’ of normality is problematic and each has caveats which diminish their acceptability. For example the concept of ‘not ill’ as a concept of normality is challenging when one looks at a variety of symptoms that would constitute illness. Johan made the point that while a symptom could indeed often be manifestation of illness, it could also be part of ‘normal’ activities of daily life. For example, the symptoms of incapacitation, pain, swelling, bleeding and infection are all used to define illness. But related to incapacitation, is sleep then abnormal, as while we sleep we are incapacitated. Similarly, child-birth is associated with pain, an erection would be a type of swelling, menstruation is a type of bleeding, and colonic fermentation a type of infection, but none of these are pathological and would be regarding as normal activities of daily living.

Regarding the concept of normality as the ‘best’ he made the point that weather that is best for agriculture is not the best for tourism. Clinically, he used the example of atherosclerosis, and the perception that reduction of the incidence of atherosclerosis would be the ‘best’ way of prolonging lifespan and creating ‘normal’ life conditions for a longer period. Johan pointed out the ideal way of reducing the incidence of atherosclerosis was either chronic under-nutrition or an early death, both of which would mean a less than optimal capacity for productivity during the life span, and therefore prolonging the lifespan by reducing atherosclerosis would not be the ‘best’ from the perspective of a ‘useful’ lifespan. Similarly, if one increased the lifespan by attenuating the incidence of atherosclerosis, one would in effect increase the levels of degenerative diseases associated with old age as a cause of death. So Johan was making the point that what is ‘best’ is clearly relative, and ‘normal’ related to ‘best’ similarly relative to the specific condition being examined, rather than life in its totality.

Johan was also critical of using ‘operating as intended’ as a state of normality, and used examples such as if the purpose of sex is procreation, then homosexuality and masturbation would be abnormal, as would bottle-feeding babies, or indeed using the tongue to lick stamps, the eyelid to wink at a friend, or the legs to kick a soccer ball rather than walking. He felt that in particular the fields of nutrition and exercise science (and one would include sociology in many ways too) were ‘guilty’ of this ‘over-simplification’ of ‘operational intent’ as normality, firstly as scientists in this field often use teleology to explain reasons why things happen in the body or what people do or eat, and / or secondly for suggesting that this purposive behaviour comes from early evolutionary processes that caused it to be so, or that illness is related to modern folk operating differently to what humans used to do. For example, some folk believe that the ‘Banting’ high fat diet was what our evolutionary ancestors must have eaten, therefore it must be ‘right’ and should be the ‘normal’ modern diet. But Johan made the point that we cannot assume the designer’s intentions are known when it comes to life processes, nor presume that there was a static nature to how things were either initially when created if a creator was involved, or when natural selection created a certain state. Rather than things being ‘at rest’ since the time they were created or selected, life processes are continually evolving, and there is therefore no immutable process or function, and normality can only really be described as its current usage, rather than as ‘operating as intended’, as we can never be really sure why or what things ultimately were intended for. Johan similarly gave short thrift to the idea that normality is related to conforming to a ‘cultural norm’, given that this definition succumbs to its own logic, given that if a definition is associated with a relative framework it can never be absolute. While some cultures love rich, salty food, others do not, as much as some cultures find it normal for men to cry, or to watch boxing or bullfighting, while other cultures would find these to be anathema. So while we often judge behaviours as normal based on cultural norms, these can never be objective.

Johan did perceive that the ‘usual’ would perhaps be the ‘best’ definition of normality, given that it allows some latitude to what normality is or is not, and allows a ‘spread’ rather than a singularity for and of normality. But again, there are the issues of specificity when describing the ‘usual’. For examples, as Johan described, it is normal for bears to sleep continuously during winter but not humans. It is normal for babies to sleep for twenty hours per day but not adults to do so similarly. It is normal for female spiders to eat the males that mate with them, but luckily for human males this is not the case in the human species. In science, we use 95% probabilities to define the ‘usual’, but this means that some ‘normal’ folk’ will always have the chance of being defined as ‘abnormal’ based on mathematical probability rather than ‘real’ illness or abnormality. But, Johan did feel that the concept ‘of usual’ was the one that was most closest to being able to define ‘normality’ (if I read this correctly in his article), particularly when one took a constellation of symptoms or actions or functions together and examined them in a gestalt manner, where they would thus be able to create a general likeness to what is the ‘normal’ human state or behaviour. He used the example of shortness of breath – it is ‘normal’ to feel short of breath when walking up a flight of stairs, but not after brushing one’s teeth. It is normal to feel short of breath when exercising, but if one feels short of breath when at rest, and it is associated with chest pain, dizziness and sweating, it would be more like that all these symptoms combined are indicative of an abnormal / ill state.

So how does all this help us with understanding normality or defining what is normal. Perhaps from all of the above, and what Johan’s article points out, it is very difficult to say with any clarity what is normal and what is not, and one should perhaps be careful when trying to do so or when defining someone’s behaviour, actions or eating behaviour as normal or not. Science often looks at one variable and based on a study makes a conclusion on whether that variable is within a normal range or not. Scientists often use ‘operating as intended’ arguments to ‘prove’ the veracity of such statements, but as Johan so well points out, whenever one uses a teleological rather than a mechanistic argument, one is moving into the realms of conjecture rather than fact. Even worse or more concerning is using ‘cultural norms’ to explain ‘normality’. While there is a place for understanding cultural differences in both health and disease, there is a very short ‘slippery slope’ from observation to prejudice when using cultural differences to label someone or some action as ‘not normal’. We are all individuals. We all have a lot of similarities. But defining normality from similarities is always going to be problematic. While our ‘gut feeling’ often correctly tells us what is normal or abnormal behaviour or actions, as Johan so well describes, the minute one tries to objectively define normality, abnormality, illness, wellness or health, one runs into problems of relativity and subjectivity. Life is always a qualitative rather than a quantitative endeavour, and our own ‘quale’ (property of life) we perceive as the life we know, is always going to be a little different, a little personal, a little subjective and never identical to anyone else’s. That makes life the wonderfully rich tapestry which it is, but of course, it makes it hard for scientists and clinicians to define normality or abnormality, and if need be, treat illness. What is normal? The question is perhaps as impossible to answer as is where we originated from, how the earth and life on it will end, or how long is a piece of string!


About Alan (Zig) St Clair Gibson

Professor Alan (Zig) St Clair Gibson MBChB PhD MD - Dean of the Faculty of Health, Sport and Human Performance, University of Waikato, New Zealand View all posts by Alan (Zig) St Clair Gibson

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