In a news story on NPR this morning, a reporter read the following sentence (or something close to it): “Both of the planes disappeared within a few minutes of each other.” I considered writing to NPR yet again to protest this manner of using “both,” but I decided to post a comment on my Web log instead. Obviously, my previous letters to NPR on the overuse of “both” have been to no avail.
I admit that the reporter’s sentence is neither false nor ungrammatical. It is true that plane A disappeared within a few minutes of the disappearance of plane B. It is equally true that plane B disappeared within a few minutes of the disappearance of plane A. The question we must ask, however, is whether only one of these assertions could possibly be true. The obvious answer is “no.” The relation disappeared within a few minutes of the disappearance of is clearly symmetric. Near simultaneity is a shared property of two events and cannot be attributed exclusively to one or the other. Particularly on the radio, where brevity is surely a virtue, the sentence should simply have been: “The planes disappeared within a few minutes of each other.” I suspect that whoever composed the sentence, however, was unconsciously using “both” as an intensifier, stressing that the crashes constituted an extraordinary coincidence.
The redundant use of “both” is common. Here are a few more examples: “Both drug stores opened near one another.” “Both boys were of equal height.” “Both speakers shared the podium.” “Both phenomena have a common origin.”
“Both” is nonetheless a useful word that is not always redundant. Consider these sentences: “Both drug stores opened is the suburb of Bethel Park.” “Both boys are 5 ft. 2 in. in height.” “Both speakers were on the 2 o’clock program.” “Both phenomena are caused by magnetic fields.”