APS Registered Replication Report Project to Explore the “Facial Feedback Hypothesis”

Editors of Perspectives on Psychological Science are now accepting proposals from researchers who would like to participate in a new Registered Replication Report (RRR) designed to replicate a 1988 experiment testing the “facial feedback hypothesis.” The experiment, originally conducted by Fritz Strack, Leonard Martin, and Sabine Stepper, investigated the hypothesis that a person’s facial expressions can influence their affective responses, an idea that dates back to Darwin.

In their study, Strack and colleagues surreptitiously induced participants to smile by holding a pen in their teeth or to pout by holding it between their lips. Although the participants were not aware of these pen-induced facial expressions, those who held the pen between their teeth (smiling) found the cartoons to be significantly funnier than did those who held the pen between their lips (pouting).

The study has been cited almost 1000 times according to Google Scholar, and it is commonly discussed in introductory psychology courses.  Although the facial feedback hypothesis is supported by other studies using different methods (e.g., Kraft & Pressman, 2012; Larsen, Kasimatis, & Frey, 1992; Soussignan, 2002), this seminal experiment has not been replicated directly using the same design and the same dependent variable.

The replication project was proposed and developed by psychological scientists E.J. Wagenmakers, Titia Beek, and Laura Dijkhoff, based on original materials provided by Fritz Strack. They normed a set of cartoons for use in the study and developed both English and Dutch versions of all of the materials. Their vetted, comprehensive protocol provides detailed, step-by-step instructions for participating laboratories and includes an instructional video. The protocol and all materials are available on the OSF website: https://osf.io/pkd65/

Researchers interested in participating in this replication project are encouraged to complete and submit a Secondary Replication Proposal Form. Participation in the project will require running the experiment in an individual lab and analyzing the data, following the detailed protocol.

All participating labs that follow the approved protocol will be included as authors on the comprehensive report that will be published in Perspectives on Psychological Science. As for all RRR projects, the results of all completed studies will be published regardless of their outcome.

The deadline to submit applications for participation in the RRR is March 23, 2015, and data collection must be completed by December 31, 2015. Note that if the editors receive a large number of applications before the March 23 deadline, the submission process may be closed early.


Kraft, T.L., & Pressman, S.D. (2012). Grin and bear it: The influence of manipulated facial expression on the stress response. Psychological Science, 23, 1372-1378.

Larsen, R.J., Kasimatis, M., & Frey, K. (1992). Facilitating the furrowed brow: An unobtrusive test of the facial feedback hypothesis applied to unpleasant affect. Cognition & Emotion, 6, 321-338.

Strack, F., Martin, L. L., & Stepper, S. (1988). Inhibiting and facilitating conditions of the human smile: A non-obtrusive test of the facial feedback hypothesis. JPSP, 54, 768-777.

Soussignan, R. (2002). Duchenne smile, emotional experience, and autonomic reactivity: A test of the facial feedback hypothesis. Emotion, 2, 52-74.


The outcome of this replication attempt will be strongly influenced by the choice of the cartoons that are used. Since the cartoons used by Strack, marin and Stepper nearly 3 decades ago in Germany are unlikely to be of the same level of funniness today in the USA (or some other country) the replication attempts will not be strinctly exact. More important, however, for people who are interested in the facial feedback theory rather than in whether holding a pen in your mouth influences your ratings of the funniness of cartoons is the conclusion we would draw if the original findings were not replicated or if the original findings were replicated in some studies but not in others.

Wolfgang – In developing the protocol, we too were concerned about differences in how people might interpret the cartoons. For that reason, the proposing team did a norming study to identify cartoons that were suitably funny (i.e., not at floor or ceiling). Moreover, if you look at the protocol, you’ll see that we have built in checks to make sure that participants found the cartoons suitably funny and that they understood them. The exclusion criteria note that we exclude data from participants whose average rating falls more than 2.5 standard deviations from the mean of their condition. And, we ask during debriefing whether they understood the cartoons. A “no” answer leads to exclusion as well. Finally, the data for humor ratings will be available, making it possible to examine whether the perceived funniness of the cartoons moderates the effect. Thus, if there are variations in how funny people find the cartoons and if that moderates the size of the effect, this study will provide enough data to test your hypothesis.

I’ll also note that labs are permitted to test other factors and conditions, provided that they do not affect the primary conditions and measurements. I believe we have differing views of the value of direct replication. But, with the possibility of testing other conditions or moderators, it’s possible to have both. The RRR itself, though, is focused on reproducing the original study as closely as possible. Fortunately, the proposing team was able to start from the original materials and had guidance from an expert in this area to make sure it was done as precisely and completely as possible.

APS regularly opens certain online articles for discussion on our website. Effective February 2021, you must be a logged-in APS member to post comments. By posting a comment, you agree to our Community Guidelines and the display of your profile information, including your name and affiliation. Any opinions, findings, conclusions, or recommendations present in article comments are those of the writers and do not necessarily reflect the views of APS or the article’s author. For more information, please see our Community Guidelines.

Please login with your APS account to comment.