Jeffrey K Aronson

The original definition of the word “bias,” when it entered the English language in the 16th century, was a diagonal line, and specifically one that cut across the warp or weft of a woven fabric. It later came to mean the tendency of a bowl, the asymmetrically shaped ball-like object used in the game of bowls, to take a curving course when rolled across a lawn, and eventually, among other things, something that produces distortion of a statistical result. Based on a study of its etymology, usages, previous definitions, and sources, I propose the following definition of a bias in research:bias, n. /ˈbʌɪəs/ A systematic distortion, due to a design problem, an interfering factor, or a judgment, that can affect the conception, design, or conduct of a study, or the collection, analysis, interpretation, presentation, or discussion of outcome data, causing erroneous overestimation or underestimation of the probable size of an effect or association [ancient Greek ἐπικάρσιος, crosswise, esp. at right angles, via French biais]This defines the count noun, a bias. The non-count noun, bias, could be defined as a tendency to produce biases.Consider three possible outcomes in an interventional study, investigating, say, a novel medicine. The medicine improves the condition, worsens it, or has no effect. How is each of these outcomes to be explained?In all cases the apparent effect could be real. The drug really does what it appears to do. However, leaving aside the possibility that the positive or negative outcome arose merely by chance, or, in the case of the no-effect result, because the study wasn’t adequately powered to detect a difference, there is always the possibility that a bias or biases of some sort played a part. Perhaps bias enhanced or impaired the response, making it appear that a positive or negative …

My list of medically related anniversaries for 2026 (events in years ending ’26 and’76) includes:• Births: Abū al-Walīd Muḥammad ibn Aḥmad ibn Rushd, the physician better known as Averroes (1126); the Flemish botanist Charles de L'Ecluse (Carolus Clusius) (1576); Amadeo Avogadro, Italian physicist (1776); Johann Spurzheim, German physician (1776); George Birkbeck, English physician (1776).• Deaths: Francis Bacon (1626); Jean Anthelme Brillat-Savarin, French lawyer and gastronome (1826); Friedrich Wilhelm Weiß, German physician and composer (1826); René Laënnec, French physician (1826); Philippe Pinel, French physician (1826); Walter Channing, American physician (1876); Victor Babe ș, Romanian physician and bacteriologist (1926); William Bateson, English biologist (1926); Emile Coué, French pharmacist and psychologist (1926); Camillo Golgi, Italian anatomist (1926); Emil Kraepelin, German psychiatrist (1926); Einar Aaser, Norwegian physician (1976); Andrew Arthur Abbie, Australian anatomist and anthropologist (1976); Jacques Monod, molecular biologist (1976); George Whipple, American physician (1976); Alexander S Wiener, American physician (1976).• Biomedical texts published: Observationes medicae circa morborum acutorum historiam et curationem by Thomas Sydenham (1676); A Comment on Forty two Histories Discribed [sic] by Hippocrates in the First and Third Books of his Epidemics by John Floyer (1726); The botanical arrangement of all the vegetables naturally growing in Great Britain by William Withering (1776); De generis humani varietate nativa by Johann Friedrich Blumenbach (1776); L'uomo delinquente ( Criminal Man ) by Cesare Lombroso (1876); Geographical distribution of animals by Alfred Wallace (1876); The theory of the gene by Thomas Hunt Morgan (1926).• Clinical therapies introduced: George Richards Minot and William Parry Murphy (treatment of pernicious anaemia with liver, 1926).• Biochemical and bacteriological observations: Karl Wilhelm Scheele (uric acid in kidney stones, 1776); Otto Unverborden (discovery of aniline, 1826); Robert Koch (the anthrax bacillus, 1876); James Batcheller Sumner (crystallisation of jackbean urease, 1926).• Establishment of the Edinburgh Medical School (1726) and of The Body Shop (Anita Roddick, 1976).• Epidemics of typhus in Spain (1576) and Ebola virus infection in Yambuku, Zaire (1976).• Nobel prizes for physiology or medicine awarded to Baruch Samuel Blumberg for identifying Australia antigen as an indicator in the blood of hepatitis B and to Daniel Carleton Gajdusek for his work on the origin and spread of infectious diseases, particularly slow virus infections and specifically kuru (both 1926), and to Johannes Andreas Grib Fibiger for discovering the Spiroptera carcinoma (1976).

Psychedelic drugs produce effects on the mind that manifest as an apparent expansion of consciousness often accompanied by hallucinations. Psychedelics, which act as agonists at serotonin 5-HT2A receptors in the brain, include psilocybin, 5-methoxydimethyltryptamine, and N,N-dimethyltryptamine (tryptamine derivatives), mescaline (a phenethylamine derivative), and lysergic acid diethylamide (LSD, a lysergamide). In his long essay The Doors of Perception Aldous Huxley stated that he had always been a poor visualiser and that words did not evoke pictures in his mind. That was consistent with a diagnosis of aphantasia, the absence of a mind’s eye. His description of his disappointing experience with mescaline was also consistent with this. When the psychiatrist Humphrey Osmond, who in 1953 had supplied Huxley with the mescaline and had supervised his use of it, invented the word “psychedelic” to describe the effects of drugs whose actions mimicked those of certain psychiatric disorders, he wrote to Huxley to tell him about it. The combination of Huxley’s aphantasia and his non-hallucinogenic response to mescaline suggests that those who have aphantasia may not respond as dramatically as others do to the actions of psychedelic drugs. However, there have been a few anecdotal reports that aphantasiacs have developed mental imagery after recreational use of a psychedelic drug. Whether psychedelics should or should not be used in aphantasiacs could be tested in formal studies, under controlled conditions, of the therapeutic actions of psychedelic drugs, such as psilocybin and mescaline, in people with the disorders for which they may be beneficial.Aldous Huxley (1894‒1963) is best known as a novelist, particularly for his futuristic science fiction novel Brave New World (1932), although most of his other well known novels were social satires.However, Huxley was also a poet and essayist, his best known essays being two that are often published together: The Doors …

Many terms have been invented to describe different types of hallucinogenic drugs, sometimes based on an analogy with the symptoms of schizophrenia, such as “psychotomimetic” and “phrenotropic.” “Psychedelics” refers to drugs that act as agonists at serotonin 5-HT2A receptors in the brain; they include psilocybin, 5-methoxydimethyltryptamine, and N,N-dimethyltryptamine (tryptamine derivatives), mescaline (a phenethylamine derivative), and lysergic acid diethylamide (LSD, a lysergamide). “Entactogens” refers to drugs that are supposed to touch you within your mind; they act by increasing release of 5-hydroxytryptamine from presynaptic serotonergic neurons and include amfetamine, methylenedioxymetamfetamine (ecstasy, E, MDMA), 5-methoxy-2-aminoindane, and the cathinones methylone and 3-methylmethcathinone. “Oneirogens” refers to drugs that induce a dream-like state similar to the oneirophrenia that is sometimes seen in schizophrenia; they include ibogaine and harmaline alkaloids. “Entheogens” refers to drugs that are used in religious rituals or to elicit a spiritual experience; they include peyote and psilocybin. However, despite the introduction of these and other terms to describe all kinds of hallucinogenic or mind-altering substances, we still don’t understand the pathophysiology of schizophrenia.The word “hallucination” comes from the past participle of the Latin verb alucinari, to wander in one’s mind, to talk idly, or to prattle. The verb to hallucinate first appeared in written English in the first monolingual English dictionary, compiled by Robert Cawdrey, A Table Alphabeticall of 1604, whose full title was A Table Alphabeticall contayning and teaching the true writing and understanding of hard usual English words, borrowed from the Hebrew, Greeke, Latine, or French, &c . Actually, that was just the first paragraph of the title, which went on after that for a further 57 words. Cawdrey defined “hallucinate” as a transitive verb, “to deceive, or blind.”Other dictionaries followed Cawdrey’s, and “hallucinate” appeared again only a few years later, in Henry Cockeram’s English Dictionarie, or …

An antedating, lexicographically speaking, is an earlier instance of the use of a word in a text than had previously been recorded. There are many examples of medical words whose earliest occurrences antedate the earliest examples given in the Oxford English Dictionary ( OED ). To mention just a few examples, they include: drip, antedatable from 1933 to 1920; lymphadenopathy, antedatable from 1920 to 1915; and medicalized, antedatable from 1970 to 1913 (in The BMJ , as it happens). And even earlier instances of those words might yet be discovered. If the several different meanings of “anamnesis,” mostly related to forms of recall, were to be listed separately in the dictionary, several antedatings could also be claimed in relation to its use to mean the medical history. When “placebo” was first treated in the OED in 1907 it was dated to 1811, in Robert Hooper’s Medical Dictionary . In the 1989 second edition, that was antedated to 1785, in George Motherby’s New Medical Dictionary , even though an earlier instance, in the clinical lectures of the Edinburgh physician William Cullen, was already known, and detailed in the James Lind Library. Now the lexicographers have further antedated the word to 1770 in the lectures of another Edinburgh physician, Andrew Duncan the Elder or Primus. Was “placebo” in its modern medical meaning coined in the Edinburgh medical school, which this year celebrates its 300th anniversary?Lexicographically speaking, an antedating is a written example of the use of a word that is of an earlier vintage than was previously recorded in a dictionary. Whenever I have surveyed medical terminology, I have found antedatings of the earliest citations in the Oxford English Dictionary ( OED ) in about 10‒15% of cases. In some cases, these have subsequently appeared in the dictionary, in other cases not. Here are some …

The term “placebo” can be dated back to at least the 1770s, the earliest recorded instances having occurred in the published lectures of two Edinburgh physicians, Andrew Duncan and William Cullen. In contrast, the term “nocebo” dates only from 1961. A nocebo effect or nocebo response can be seen to have occurred when, adapting the Oxford English Dictionary ( OED ) definition, one or more adverse effects are reported after administration of a placebo. Compared with placebos and the placebo effect, nocebos and the nocebo effect have been little studied, and many of the published papers that feature discussion of nocebos are non-systematic reviews. To quote the old academic phrase, which, although trite, on this occasion is nevertheless apposite, “more research is needed.”Tracing the earliest examples of the written use of the word “placebo” has been a relatively slow process. By “placebo” I mean, as it is defined in the Oxford English Dictionary ( OED ), “A drug, medicine, therapy, etc., prescribed more for the psychological benefit to the patient of being given treatment than for any direct physiological effect; esp. one with no specific therapeutic effect on a patient's condition, but believed by the patient to be therapeutic (and sometimes therefore effective). Also: a substance with no therapeutic effect used as a control in testing new drugs, etc.; a blank sample in a test.”1When “placebo” was first treated in the first edition of the OED , in the fascicle Piper‒Polygenistic, published in March 1907, the earliest instance was dated to 1811, in Robert Hooper’s Medical Dictionary , even though earlier versions of the definition used at that time (“An epithet given to any medicine adapted rather to please than benefit the patient”) had been published, going back to 1787.2 In the 1989 second edition of the OED , that …

The number of centenarians in the UK in 1951 was counted at 271. Since then, the number has increased exponentially, with a doubling time of about 12 years; it was estimated at 16 640 in 2024. Different environmental factors will have contributed to this striking increase, but the extent to which each has done so is not known. They include improvements in healthcare, including pharmacological therapies, dietary interventions, and increased participation in forms of exercise, and reduced atmospheric pollution, beginning with the Clean Air Acts of the 1960s. Increased rates of obesity may have militated against the trend, but better treatments may start to reverse that. The association of some genes with certain preventable or treatable diseases, and even the possibility that some genes may be independently associated with longevity, suggests another strategy—that of choosing one’s parents carefully.The hundredth anniversary of the birth of Sir David Attenborough on 8 May 1926 is being celebrated today, justifiably, not merely because of the achievements of the man himself, but also because it reminds us that more people than ever before are living to the age of 100 years and over. Another example, in the medical field, was Harold Ellis, the surgeon whose textbook, Clinical Anatomy , in its 14 editions, has been so influential in teaching generations of medical students, and who died recently having just attained the age of 100. I have just tucked a copy of his obituary into my copy of the 3rd edition of 1966, which opened my eyes to the clinical relevance of the anatomy that I had been struggling to understand in the dissecting room.Those who live to be 100 years old are called centenarians, from the classical Latin adjective centenarius, referring to something that is or contains a hundred of anything, or more specifically, …

The American journalist Ambrose Bierce is best known for the book called The Devil’s Dictionary , a collection of wryly amusing definitions, often pejorative. Several of them may be of interest to healthcare professionals. However, those of a weak disposition might do better not to read any furtherAmbrose Gwinnett Bierce (1842-1914?) was an American writer. The query against his dates is there because in late 1913 he left America and went to observe the Mexican revolution; he was never seen again. Most of the following information about his life comes from Richard O’Connor’s 1967 biography.1Born in Ohio, Bierce fought on the Union side in the Civil War, then found a job working in the United States Mint in San Francisco, where, preparing himself for a career as a writer, he found the time to read widely, working his way through authors such as Gibbon, Burke, Spencer, and Pope, although he soon came to model himself on American writers such as Bret Harte and Mark Twain. In the 1860s he started to contribute articles to San Francisco periodicals. He wrote verse for The Californian , and articles for the San Francisco News-Letter under the heading “Town Crier.”The editor of the News-Letter , James Watkins, further moulded Bierce’s style by introducing him to the satirical writings of Swift and Voltaire and to Thackeray’s effortless prose. Bierce’s contributions were later described as having “a Rabelaisian audacity which stands abashed at but very few things indeed” and elsewhere as being “pervaded by a new and puzzling flavor that was a combination of eccentric wit and utterly unconventional form.”In 1872, Bierce and his wife, Mollie Day, not long married, left America for England, where they lived until 1875, at first in London and later in Bath and Leamington. There Bierce …

Ambrose Bierce’s collection of satirical definitions, The Devil’s Dictionary , has had many modern imitators, of which Michael O’Donnell’s collection A Sceptic’s Medical Dictionary , is one. Together they add a sixth entry in my collection of types of skepticism, previously limited to five: philosophical, Voltairian, scientific, dogmatic, and nihilistic. I have called the sixth type satirical skepticism.If you look up the word “skepticism” in any good English dictionary you will find that it has an alternative spelling, “scepticism.” In some cases, you’ll be told that the spelling with a /k/ is “usually US.”The word comes from the hypothetical Indo-European root SPEK, to see or regard. In Greek, metathesis of the P and K led to the verb σκοπεῖν, to look, see, watch, or regard, its related deponent verb σκέπτεσθαι, to consider, and the adjective σκεπτικός, thoughtful.In Latin, however, the Greek word σκεπτικός became scepticus, the two Greek kappas being turned into Roman cees. Hence the two different spellings of the English word skeptic/sceptic and its derivatives.In a PubMed search of the titles and abstracts of indexed papers, skeptic/sceptic and its derivatives in the versions with a /k/ are found more than twice as frequently as the versions with a /c/ and this falls to just under twice as frequently when taking into account papers originating from the USA. However, in papers originating from the UK, the spelling with /c/ is about twice as common. These are crude measures, but they suggest that the version with a /k/ is more often used in worldwide bioscience papers than the version with a /c/ but not in the UK.In previous discussions of skepticism I have recognised five types: philosophical, Voltairian, scientific, dogmatic, and nihilistic.1Philosophical skepticism The ancient Greek school of philosophers known as Skeptics, founded …

Four members of the Darwin family were students at the Edinburgh Medical School, three of them in the second half of the 18th century—Erasmus and his two sons, Charles and Robert, and one in the early 19th century—Robert’s son Charles. The younger Charles found the study of medicine boring and didn’t qualify, but became more famous than all the others. The older Charles, the younger Charles’s uncle, would have qualified, but died before he could submit his graduation dissertation; he may have developed meningococcal septicaemia after dissecting the body of a child with hydrocephalus. Erasmus and Robert pursued successful careers in medicine.The Edinburgh Medical School was founded as a Faculty of Medicine within Edinburgh University in 1726, 300 years ago this year.1 It was the first such in the English-speaking world, at a time when medical training in the UK was largely achieved through apprenticeships to apothecaries, surgeons, and physicians. Those who wanted to attend a medical school had to travel to the Continent, to schools such as those at Leiden and Padua. With its new medical school, Edinburgh was able to attract students who did not want to travel abroad or who could not afford to. As a result, its teachers and alumni were of exceptionally high quality, and the school consequently developed a reputation as the best in the country, even when other schools were founded. Many of its alumni became household names in various fields of medical practice, and not infrequently in other areas as well.The English physician Erasmus Robert Darwin was born in 1731, just five years after the foundation of the Edinburgh Medical School.2 He was educated first at Chesterfield School, from 1741 to 1750, then at St John’s College, Cambridge, taking the degree of BA in 1754. During …