between and among

How to distinguish “between” and “among”

The common advice these days is that “between” should be reserved for the comparison of just two entities, and if there are more than two, “among” should be used. What is wrong with this advice? Consider what the OED online has to say:

“V. 19. In all senses, between has been, from its earliest appearance, extended to more than two. In OE. and ME. it was so extended in sense 1, in which AMONG is now considered better. It is still the only word available to express the relation of a thing to many surrounding things severally and individually, among expressing a relation to them collectively and vaguely: we should not say ‘the space lying among the three points,’ or ‘a treaty among three powers,’ or ‘the choice lies among the three candidates in the select list,’ or ‘to insert a needle among the closed petals of a flower.’”

Thus, according to the OED, the common advice is wrong because it leads to an incorrect use of “among.” Merriam-Webster Online has a similar opinion, as quoted at the end. In my opinion, having a different word when there are more than two things in a comparison or relationship is awkward and unhelpful. Instead, it is a hoop for authors to jump through that reduces clarity. It is an inhibition to understanding by making a pointless distinction. Making the distinction that the OED advocates is useful because it is a distinction about the nature of the relationship.

Consider the case of two different studies, one involving two species that reports foraging differences between species, and another involving three species that reports differences among species. These studies have findings that are, to all intents and purposes, the same. Hence, it is unhelpful to have the language make them seem different. The fact that this rule is unhelpful is perhaps the reason why it is commonly incorrectly implemented, with “among” often being used for pairwise comparisons. The following quotations are inconsistent with both the OED advice, and the common advice to use “between” for two and “among” for more than two.

Connell, J. H., T. P. Hughes, C. C. Wallace, J. E. Tanner, K. E. Harms, and A. M. Kerr. 2004. A long-term study of competition and diversity of corals. Ecological Monographs 74:179-210.

“To test the hypotheses about competition listed in the Introduction, we summarized the data for all the observed encounters between corals over all years in the study period as a matrix of the interactions among species at each site at each quadrat (Appendices C, D, and E). We also used the matrices to describe the competition in two other ways.”

Nathan, R., G. G. Katul, H. S. Horn, S. M. Thomas, and R. Oren. 2002. Mechanisms of long-distance dispersal of seeds by wind. Nature 418:409-413.

“Therefore, despite the differences among means, the two samples appear to come from the same population.”

Webb, C. O., D. D. Ackerly, M. A. McPeek, and M. J. Donoghue. 2002. Phylogenies and community ecology. Annual Reviews of Ecology and Systematics 33:475-505.

“This would lead to weaker pairwise interactions among sister taxa.”

Elizabeth Pennisi, “The Case of the Disappearing DNA Hotspots” Science 11 June 2004, p 1590

“DNAwise, chimps and humans are virtually identical. But two research teams have found, to their surprise, key differences among these close cousins in the locations of DNA recombination hotspots: places where matching chromosomes exchange DNA much more frequently than normal.”

Wayne, R. K., Morin, P. A. 2004. Conservation genetics in the new molecular age. Frontiers in Ecology and the Environment 2, 89-97.

“Breeding among close relatives leads to a reduction in genetic variability and increases the likelihood that genes having a deleterious effect on fitness will be expressed.”

The following quotation illustrates the way "among" is commonly used these days, against the OED advice, with the intention of indicating relationships:

From NSF fastlane:

“NSF cannot achieve its ambitious goals for the science and technology base of our country with its own resources alone. So we place strong emphasis on working in partnership with other public and private organizations engaged in science, engineering, and education and on encouraging partnerships among such organizations. We also seek partnerships across national boundaries, working with comparable organizations in other countries wherever mutually beneficial.”

The italics above are NSF’s. The “among” above, of course, should be “between.” Taken literally, as I believe "between" and "among" should be used, the statement implies that the intended partnerships are not relationships between the aforementioned organizations, but are themselves organizations, which are found when searching among these organizations. As a partnership can be an organization, for instance, one can invest in a partnership, NSF's usage does have some potential to cause confusion. Alternatively, if partnerships are not organizations, they might be read as another sort of entity found when looking among organizations, just as one might find women among men in a room full of people.

From Padian, K. 2008. Darwin's enduring legacy. Nature 451, 632-634:

"In Darwin's day, dispersal through migration was the only mechanism thought possible for species to move among continents."

Most stylists, even if they disagree with my approach, would say that "species move between continents," not "among" them because species move from one continent to another, not several simultaneously. Following most rules, this statement suggests that Padian is speaking of marine species that do not actually go from continent to continent but are in the ocean among the continents.

How should "among" be used? Here's an example: "Among the fish in a pond, one finds some that are highly cryptic." Note that "between" would not work here. With this usage, it is instructive to consider the quotation from Wayne et al, above. "Breeding among close relatives" would not mean that they are breeding with each other, but that given a group of close relatives, one can expect to find breeding, and the consequences would be deleterious. By substituting "between" above, it is specified that they are breeding one with another, and not, for example, selfing.

If your copy editor or colleague insists that you stick with the silly knee-jerk rule of "use between when there are only two items, but among for more than two," send them to this page.

What Merriam-Webster Online has to say:

"usage There is a persistent but unfounded notion that between can be used only of two items and that among must be used for more than two. Between has been used of more than two since Old English; it is especially appropriate to denote a one-to-one relationship, regardless of the number of items. It can be used when the number is unspecified <economic cooperation between nations>, when more than two are enumerated <between you and me and the lamppost> <partitioned between Austria, Prussia, and Russia — Nathaniel Benchley>, and even when only one item is mentioned (but repetition is implied) <pausing between every sentence to rap the floor — George Eliot>. Among is more appropriate where the emphasis is on distribution rather than individual relationships <discontent among the peasants>. When among is automatically chosen for more than two, English idiom may be strained <a worthy book that nevertheless falls among many stools — John Simon> <the author alternates among modern slang, clichés and quotes from literary giants — A. H. Johnston>."

See also the following.
betweenness between'ness n.

USAGE NOTE According to a widely repeated but unjustified tradition, “between is used for two, and among for more than two.” It is true that between is the only choice when exactly two entities are specified: the choice between (not among) good and evil, the rivalry between (not among) Great Britain and France. When more than two entities are involved, however, or when the number of entities is unspecified, the choice of one or the other word depends on the intended sense. Between is used when the entities are considered as distinct individuals; among, when they are considered as a mass or collectivity. Thus in the sentence The bomb landed between the houses, the houses are seen as points that define the boundaries of the area of impact (so that we presume that none of the individual houses was hit). In The bomb landed among the houses, the area of impact is considered to be the general location of the houses, taken together (in which case it is left open whether any houses were hit). By the same token, we may speak of a series of wars between the Greek cities, which suggests that each city was an independent participant in the hostilities, or of a series of wars among the Greek cities, which allows for the possibility that the participants were shifting alliances of cities. For this reason, among is used to indicate inclusion in a group: She is among the best of our young sculptors. There is a spy among you. Use between when the entities are seen as determining the limits or endpoints of a range: They searched the area between the river, the farmhouse, and the woods. The truck driver had obviously been drinking between stops.

The above passage came up on interrogating "between" on the New York Times site, and is attributed to

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.