Image edited by Web Investigator – Participants in the ‘Loucura Suburbana’ (Suburban Madness) Carnival street parade organised by the Nise da Silveira mental health institution, February 2014 in Rio de Janeiro, Brazil. The ‘bloco’ aims to integrate patients with neighbourhood residents while promoting acceptance and blurring the lines defining mental illness. Photo by Mario Tama/Getty
Are you average? Typical? Ideal? Adequate? The idea of ‘normal’ is a historical construct and it’s time we got rid of it
The problem of variation haunts medical science. In the 19th century, one of the founders of experimental medicine, the French physiologist Claude Bernard, claimed that individual variability was an obstacle to medical judgment. If we could show that the abnormal was a mere quantitative deviation from the normal, he wrote, we would possess the key to treating any given individual, no matter how he or she veered from the rest. After all, if the pathological is merely a deviation from the normal, then not only the aim but the very possibility of the therapeutic act becomes clear: return the sick individual, organ, cell or system back to a normal state.
This view still guides much of biomedical research; organisms, cells, gene networks and more are routinely perturbed to determine how these systems ‘normally’ function. Researchers disrupt or destroy in order to establish standards and to develop new treatments.
But what are we talking about when we talk about normal physiology? If, as the philosopher Sara Moghaddam-Taaheri wrote in 2011, we see abnormality not as ‘broken normal’ but as a qualitatively different state, it would be difficult to understand how such interventions could restore the sick to health.
While medical researchers might miss such fine points, philosophers of medicine have been parsing the nuances and striving to define ‘normal’ for years. One thought experiment asks us to consider variations on the ends of the spectrum that we would not consider pathological: having green eyes, being colour-blind, being extremely tall or short, having photographic memory, or being a supertaster. These contrast with conditions that could be problematic only in some environments, such as the inability to repair UV damage; with variations that disadvantage only in some cultures or times periods, such as albinism or hearing voices that aren’t there; and with variations so extreme (Tay-Sachs disease, for instance) that they prevent overall functioning.
Yet, even then, life can find a way. For example, there are individuals with a high IQ and otherwise ‘normal’ social life despite having hydrocephalus, a condition in which excessive fluid in the ventricles of the brain enlarges the skull and often results in severe brain damage. How can normality be a scientific concept when its spectrum is so vast? What is normality, really? Do we grasp its meaning? How does one conform to norms?
The Czech philosopher Jiří Vácha provided a helpful taxonomy of normality’s various meanings in 1978. Normality could mean frequent in the sense of being the most common within a population, such as having brown eyes in Mediterranean countries or blue eyes in Nordic countries. It could mean average in the sense of a mathematical mean, such as the average weight or height of a population, often represented with the familiar bell curve, or typical, as in representative of a group, population or general type. Sometimes, normal meant adequate in the sense of being free from defect, deficiency or disorder, and other times it meant optimal in the sense of peak functioning – being physically fit or mentally sharp. Or, it could refer to an ideal Platonic essence, as in the perfect beauty or the perfect body. Finally, there is our basic everyday usage of the word, which often slip-slides among these different meanings and tropes, from the orthodox and standard to what is expected and good.
In any parlance, the specific meaning of ‘normal’ has important consequences, especially if it is given a privileged position in the world. Anything that veers – from having green eyes or hearing voices to living with hydrocephalus – would be abnormal in one sense or another: uncommon, rare, atypical, potentially inadequate, suboptimal or deficient in some way – and in need of being brought back to some norm. Yet, it could be controversial, or just plain odd, to pathologise such variations; especially if they are functional in some way…