A recent opinion piece argued that “the ‘death with dignity’ mantra appeals most to that cohort of people who believe they can control the end of their lives.”
The headline on another article in the same publication read: “Prosecutors: Gang member killed man who pursued charges against his cohort.” The article didn’t use the word “cohort”; the suspect was accused of killing a man who had testified against a member of the suspect’s gang.
Two uses of “cohort,” one to describe a group of people and one to describe an individual, but both singular.
Not too long ago, anyone using “cohort” in either of those ways might have come under fire. The 1949 Webster’s New Collegiate Dictionary defines “cohort” as “In the Roman army, one of the ten divisions of a legion,” or “A company or band, especially of warriors.” As a collective noun, it had no plural, since it was the group of individuals, and not the individuals themselves who made up the “cohort.” By the 1957 edition of Webster’s New World Dictionary, “cohort” had acquired a less military definition: “now, often, an associate or colleague,” with an example “the mayor came with one of his cohorts.” It also acquired a greater ability to be plural.
Nowadays, the military definition has fallen out of favor: Webster’s New World College Dictionary, which gives definitions in historical order, now has five uses for “cohort”:
1 an ancient Roman military unit of 300-600 men, constituting one tenth of a legion
2 a band of soldiers
3 any group or band
4 an associate, colleague, or supporter [one of the mayor’s cohorts]
5 a conspirator or accomplice
6 a subgroup sharing a common factor in a statistical survey, as age or income level
And because “a cohort” can mean a group or an individual, make sure your context is clear: “I treated my cohort to a ballgame” could mean you sprung for one ticket or for many.
Journalists seem to be using “cohort” a lot more, but often in place of “group.” “Cohort” may make it sound more serious, but it can also confuse readers who have to stop and think whether you mean a group, a subset of a group, an individual, or something sinister.
For example, a “business accelerator” chose “six new start-up companies for its latest cohort,” an article said. What’s the matter with describing the six companies as a “group,” especially when combined with the jargon of “business accelerator”? Better yet, just say that “a business accelerator chose six new start-up companies for financial help in building their businesses.” If you must use “business accelerator” at all.
Another “cohort” of journalists who like “cohort” are education reporters. “Caddo Schools improved its cohort graduation rate by 7.5 percent in a year — the largest growth in the region,” another article said. Though the article used “cohort” nine times, it never defined the “cohort.”
The term “cohort” appeared nearly 1,000 times in education stories in news reports in just the past three months, according to a Nexis search that filtered out academic journals, and few defined “cohort” in this context.
If you must know, here’s the most helpful definition we could find, from a 2008 Department of Education document:
From the beginning of 9th grade, students who are entering that grade for the first time form a cohort that is subsequently “adjusted” by adding any, who transfer into the cohort later during the 9th grade and the next three years and subtracting any students who transfer out, emigrate to another country, or die during that same period.
In other words, this “cohort” is the group of students who graduate on schedule, in four years.
The statistical precision of adding the people who arrived and subtracting the people who left may be needed in academic or scientific contexts, but do readers really need to be saddled by that? Wouldn’t it have been better to say “The rate of students who graduated from Caddo Schools on time …” and explain what that meant in terms readers can understand?
After all, readers are the most important “cohort” to be taken into account.