Thinking, Fast and Slow · chapter 7 · id thinking-fast-and-slow-c7-01-holding-a-pen-in-your-teeth-fo

“Holding a pen in your teeth (forcing a smile) makes cartoons funnier, demonstrating that facial expressions directly influence emotional experience (facial feedback hypothesis).”

contestedconfidence: high✓ ZHP-verified + red-teamed

Receipts

Strack, Martin & Stepper (1988), JPSP 54(5)DOI registry: valid

Participants holding a pen in their teeth (facilitating a smile) rated cartoons as funnier than those holding a pen with their lips (inhibiting a smile). N=92.

Wagenmakers et al. (2016), Registered Replication Report, Perspectives on Psychological Science 11(6)DOI registry: valid

Across 17 labs and 1,894 participants, the overall effect was essentially zero (d = 0.03). The replication failed to find the original effect.

Coles, Larsen & Lench (2019), Psychological BulletinDOI registry: valid

Meta-analysis of facial feedback studies more broadly found a small but statistically significant effect (d ~ 0.20), suggesting the broader hypothesis has some support even if the specific pencil paradigm did not replicate.

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