Influence: The Psychology of Persuasion · chapter 1 · id influence-c1-03-ellen-langers-copy-machine-stu

“Ellen Langer's 'copy machine' study (1978) showed that simply adding the word 'because' to a request -- even with a meaningless reason -- dramatically increased compliance from 60% to 93%.”

contestedconfidence: high⚠ extracted by pipeline, re-audit pending

Receipts

Langer, Blank & Chanowitz (1978), Journal of Personality and Social Psychology 36(6)DOI registry: valid

For the small-favor condition (5 pages), 94% complied with a real reason, 93% with a placebic reason ('because I have to make copies'), and 60% with no reason.

Langer et al. (1978) -- large request conditionDOI registry: valid

For the large-favor condition (20 pages), the placebic reason compliance rate dropped to 24%, while real reason was 42% and no reason was 24%. The 'because' effect vanished for larger requests.

Bohns et al. (2021), Personality and Social Psychology Bulletin 47(7)FLAGGED: DOI not in registry

Partial replication: the 'because' effect was smaller than originally reported and moderated by request size and perceived legitimacy of the reason.

This claim is a stable, citable object. If you can falsify a verdict, tell us — corrections are loud here.