I realize that this has been discussed elsewhere on the site, but I was interested in the use of the preposition "among" in a sentence from a story in yesterday's New York Times:
Research done by Emmanuel Saez, left, and Thomas Piketty has shown that inequality among the middle class and the rich is nearly as acute as it was before the Great Depression.
My first impression was that the sentence was incorrect, and that "between" should have been used instead. After thinking about it for a minute, however, it seems like the use of either preposition may be valid, but that the sentence would mean different things depending on the choice. With "between", the sentence is referring to inter-group differences between the incomes of the rich and the middle class. With "among", the sentence is referring to intra-group differences in income among the individual members of each particular group.
Honestly I have no idea if this interpretation is correct. Can someone please clarify this for me?
Best Answer
It strictly is neither intra- nor inter-group, as the context shows.
As you seem to know already, it is between two objects, and among more than two.
The differences referred to are between (each individual member of one group) and (each member of the other) -- a many-to-many relation, so we need among here.
intra: The juniors are quiet, but the seniors fight among themselves.
inter: There will be a friendly match between the seniors and the juniors.
Our case: There are friends among the juniors and the seniors.
inter, 1-to-1: There will be boxing contests between the juniors and the seniors.