In "They fought among themselves", themselves is actually reciprocal rather than reflexive: it's not each one fighting with himself, but all fighting with each other. Is this use restricted to the preposition "among" or does it occur in other contexts as well?
The earliest evidence of themselves referring to plural they or them is from 1466, and the earliest evidence of themselves referring to singular they or them is from 1529. Meanwhile, themself was used for the plural from at least 1382 (and possibly for close to 200 years before that), and for the singular from 1450. https://www.merriam-webster.com/words-at-play/themself
--Backinstadiums (talk) 19:58, 28 March 2020 (UTC)
https://www.wordreference.com/definition/themselves --Backinstadiums (talk) 10:00, 24 July 2021 (UTC)
ˈðem selvz occasionally with contrastive stress JMGN (talk) 16:58, 21 June 2024 (UTC)