And a little further on in the article De Gray is quoted as saying:“De Gray has by his vigorous efforts brought together a COHORT of responsible scientists who see just enough theoretical value in his work to justify not only their engagement but their encouragement.”
Now I’m sure that many people knew that ‘cohort’ was both singular and plural, but I am somewhat embarrassed to say that I was not among them (these things happen). And perhaps the biggest influence on my mistaken belief was Bryon’s famous poem ‘The Destruction of Sennacherib (1815), which I liked the sound of and memorized in high school, and since then, for some reason, never gave it a second thought. The only trouble was that I didn’t realize that when Byron said ‘cohorts' he wasn’t implying that ‘a cohort’ was a single soldier:"If we hesitate and vacillate in developing life-extension therapy, there will be some COHORT to whom we will deny the option to live much longer than we do. We have a duty not to deny people that option."
So, for those who have lived in ignorance, as I have, all these years, here is a little bit on the subject of ‘cohort.’The Assyrian came down like the wolf on the fold, / And his COHORTS were gleaming in purple and gold; /And the sheen of their spears was like stars on the sea, / When the blue wave rolls nightly on deep Galilee. / . . . . .
COHORT noun: 1) a group or band of people <“She has a cohort of admirers.”> a generational group as defined in demographics, statistics, or market research <“The cohort of people aged 30 to 39 . . . were more conservative”> 2) a companion, associate; follower; an accomplice or abettor <“The congressman was accompanied by a group of loyal cohorts”> <“He got off with probation, but his cohorts got ten years apiece.”> 3a) One of the 10 divisions of a Roman legion, consisting of 300 to 600 men. 3b) any group of soldiers or warriors 4) Biology: an individual in a population of the same species.
Etymologically, ‘cohort’ is an enclosed yard. ‘It came into English (1489) via Old French from the Latin ‘cohors,’ a compound noun formed from the prefix ‘co’ meaning ‘with’ + the element ‘-hort’ which also appears in Latin ‘hortus,’ garden’ (source of English ‘horticulture’) and which is related to English ‘garden,’ ‘yard,’ and ‘orchard.’ From the underlying sense of ‘enclosed place,’ ‘cohort’ came to be applied to a group of people in such a place. Later, ‘cohort,’ similarly, from the concept of ‘enclosed yard,’ was applied to sections of an army camp, and this was then applied to the unit quartered in that section. And so it came to mean an infantry company in the Roman army, specifically, a military unit made up of one tenth of a Roman legion. By a somewhat different route through French, ‘cohors’ yielded the English word ‘court’ – a development that makes more sense in relation to cognates like ‘yard’ and ‘garden’ than does to the military unit.
The ‘cohort’ was one of the tactical units that helped produce the Roman Empire, and hence it became a necessary word in English in translating and for writing about Roman history. Once established in English, it began to develop subsidiary senses, as it had in Latin. One of the earliest developments in English was the extension to any body of troops – a meaning that in Latin had actually preceded the ‘tenth of a legion’ sense. And this was the meaning that Byron was using, where a ‘cohort’ was a group of soldiers and ‘cohorts’ were groups of groups of soldiers. And, incidentally, the use of the word ‘cohorts’ in Byron’s poem is an anachronism, since the battle he speaks of took place and the Assyrian Empire fell long before the Roman word ‘cohort’ was invented.
‘Cohort’ by the early 18th century had come to be applied to any group united in a common cause, especially friends, supporters, or adherents – a band of associates (this sense had also existed in Latin), but it was not used to mean a single individual. However, the often mistaken use in the U.S. of ‘cohorts’ (as a group of individuals and not group of groups) in the mid-20th century led to the adoption of ‘cohort’ as a single ‘associate’ or an ‘accomplice.’ This usage was not readily accepted by most grammarians, but Americans heartily embraced it in the 1940s and 1950s. This widespread U.S. misuse of the word also dribbled back across the Atlantic, but according to the OED it is not as widely used there, and it lists this usage as ‘chiefly U.S.’
So, the mighty tenth of a Roman legion had been reduced, at least by most Americans (including this one), to one lousy companion, while the collective group ‘cohort’ had been widely transformed into ‘cohorts.’ At about the same time that the word ‘cohort’ was being mangled in America it acquired, a new meaning which was first applied in demography to a group of people having a common statistical characteristic (e.g. ‘birth cohort’ – group born in same year; and a bit later ‘baby-boomer cohort’ – group born between 1946 and 1965), and so the idea of a group ‘cohort’ gained some reinforcement and revitalization. But over the last 25 years or so the most common use, at least in the U.S., appears to have been the singular sense of a ‘colleague, associate, companion.’ It should be noted, though, that this newer meaning is still frowned upon by some and is considered informal by many word mavens who suggest that in formal writing, only the older sense should be used. And here I sat all this time, not a complete illiterate, I hope, and probably not nearly alone, not even aware that the ‘proper’ sense existed. And as a word of encouragement to all those disgruntled mavens, I say, ‘good luck in the U.S.A.!’
Note: 1) In De Gray’s second quote above, ‘cohort’ could be interpreted either as a statistical group or as a single person, but in the context of this discussion of biogerontology, he is most likely referring to the group. 2) Another example of a collective sense coming to denote a single person is the word ‘comrade,’ but that’s another story.
(Merriam-Webster New Book of Word Histories, Dictionary of Word Origins by Ayto, Barnhart Concise Dictionary of Etymology, Random House and Merriam-Webster’s Unabridged Dictionaries, Oxford English Dictionary, New Fowler’s Modern Usage by Burchfield, Garner’s Modern American Usage)<1489 “A COHORTE of Macedonyens.”—‘Book of Fayttes of Armes and of Chyualrye,’ translation, II. v. page 99>.
<1667 “The COHORT bright Of watchfull Cherubim.”—‘Paradise Lost’ by Milton, XI. line 127>
<1719 “My friends and my acquaintance . . . I had a numerous COHORT of the latter.”— ‘Works’(1841) by Bolingbroke in “Swift’s Correspondence,” II. page 543>
<1871 “A small COHORT of social regenerators.”–‘Fragments of Science for Unscientific People’ (edition 6) by Tyndall, II. xvi. page 454>
<1944 “‘COHORT’ (demographical usage), a group of persons starting life together. Thus, hypothetical COHORTS are established in the construction of life tables.”—‘Dictionary of Sociology’ by H. P. Fairchild, page 45/2> [first appearnace as a demographic group]
<1952 “The old poet had left, accompanied by two of his COHORTS.”—‘The Groves of Academe’ by M. McCarthy, xii. page276> [first appearance in which ‘cohort’ means single ‘colleague’]
<1957 “Banting [was] assisted by his young COHORT, Dr. Charles H. Best. The culprit and his three COHORTS quickly confessed.”—‘Dictionary of Contemporary English Usage’ by B. & C. Evans, page 99/1>