Both forms of the word are acceptable. “Among” is more common, however, perhaps because “amongst” sounds a bit old-fashioned. For that reason, I invariably change “amongst” to “among when editing – unless the book is a historical novel or a sword and sorcery tale. As a side note, most publishers prefer “among” as it’s shorter and so takes up less space.
My name is Rob Bignell. I’m an affordable, professional editor who runs Inventing Reality Editing Service, which meets the manuscript needs of writers both new and published. I also offer a variety of self-publishing services. During the past decade, I’ve helped more than 300 novelists and nonfiction authors obtain their publishing dreams at reasonable prices. I’m also the author of the 7 Minutes a Day… writing guidebooks, four nonfiction hiking guidebook series, and the literary novel Windmill. Several of my short stories in the literary and science fiction genres also have been published.