Inhibiting and facilitating conditions of the human smile by Fritz Strack and others (1988)

Primary publication: doi.org/10.1037/0022-3514.54.5.768

Publication text or primary record: jhrcook.github.io/wagenmaker-data-analysis/papers/Strack_1988_Inhibiting-and-facilitating-conditions-of-the-human-smile-a-nonobtrusive-test-of-the-facial-feedback-hypothesis.pdf

Journal of Personality and Social Psychology 54, 768–777; pen manipulation and humor responses.