Strack's study asked participants to hold a pen in their mouths in such a way as to make them either smile or frown, and then had them rate how funny a series of the Far Sidecartoons were. In this study, participants who were smiling rated the cartoons as funnier, on average, compared to those who were frowning. In 2016, a study by a separate research team was published which failed to replicate the original study's results. Strack himself suggested that the negative results of the replication study may have been caused by its researchers' use of a video camera to record the participants' responses. He also took issue with the replication study's choice of the same cartoons that had originally been used in 1985. Subsequent research has supported Strack's claim that participants knowing they are being recorded by cameras led to the replication study's negative result. Further evidence has provided additional support for both the pen procedure and the validity of the facial-feedback hypothesis.
↑Strack, F.; Martin, L. L.; Stepper, S. (May 1988). "Inhibiting and facilitating conditions of the human smile: a nonobtrusive test of the facial feedback hypothesis". Journal of Personality and Social Psychology. 54 (5): 768–777. doi:10.1037/0022-3514.54.5.768. ISSN0022-3514. PMID3379579. S2CID15291233.
↑Strack, F. (2016). Reflection on the smiling registered replication report. Perspectives on Psychological Science, 11(6), 929–930. https://doi.org/10.1177/1745691616674460
↑Noah, Tom; Schul, Yaacov; Mayo, Ruth (May 2018). "When both the original study and its failed replication are correct: Feeling observed eliminates the facial-feedback effect". Journal of Personality and Social Psychology. 114 (5): 657–664. doi:10.1037/pspa0000121. ISSN1939-1315. PMID29672101. S2CID4985655.
↑Coles, N. A., Larsen, J. T., & Lench, H. C. (2019). A meta-analysis of the facial feedback literature: Effects of facial feedback on emotional experience are small and variable. Psychological Bulletin, 145(6), 610-651.
↑Marsh, A. A., Rhoads, S. A., & Ryan, R. M. (2018). A multi-semester classroom demonstration yields evidence in support of the facial feedback effect. Emotion, 19(8), 1500–1504.