[Excerpts are taken from the article “Can Smiling Really Make You Happier?” by Cathleen O’Grady, published at FiveThirtyEight.com]

“In 1988, social psychologist Fritz Strack published a study that…asked participants to…hold a pen in their mouths in a position that forced them either to bare their teeth in a facsimile of a smile or to purse their lips around the pen…When both groups were shown a set of newspaper comics…the teeth-barers rated the images as funnier than the lip-pursers did.”

“…Even though participants weren’t thinking about smiling or their mood, just moving their face into a smile-like shape seemed to affect their emotions…Decades of corroboration followed, as researchers published other experiments that also showed support for the facial feedback hypothesis.”

“But in 2016, all at once, 17 labs failed to replicate the pen study. Those 17 studies, coordinated by Dutch psychologist E.J. Wagenmakers, repeated the original study as closely as possible to see if its result held up, with just a few changes…When all 17 studies failed to replicate the original result, the effect was “devastating for the emotion literature,” said Nicholas Coles, a psychology grad student whose research focuses on the facial feedback effect.”

“But as powerful as multi-lab replication efforts like these are, they aren’t necessarily the last word.”

“When Wagenmakers and his colleagues published their replication study in 2016, Coles was digging deeply into the facial feedback literature. He planned to combine all of the existing literature into a giant analysis that could give a picture of the whole field. Was there really something promising going on with the facial feedback hypothesis? Or did the experiments that found a big fat zero cancel out the exciting findings? He was thrilled to be able to throw so much new data from 17 replication efforts into the pot.”

“He came up from his deep dive with intriguing findings: Overall, across hundreds of results, there was a small but reliable facial feedback effect. This left a new uncertainty hanging over the facial feedback hypothesis. Might there still be something going on — something that Wagenmakers’s replication attempt had missed?”

“Coles didn’t think that either Wagenmakers’s replication or his own study could put the matter to rest…So he set about designing a different kind of multi-lab collaboration. He wanted not just to replicate the original study, but to test it in a new way. And he wanted to test it in a way that would convince both the skeptics and those who still stood by the original result.”

“He started to pull together a large team of researchers that included Strack. He also asked Phoebe Ellsworth, a researcher who was testing the facial feedback effect as far back as the 1970s, to come on board as a critic.”

“Coles’s group, called the Many Smiles Collaboration…is based on the pen study from 1988, but with considerable tweaking. Through a lengthy back-and-forth between collaborators, peer reviewers and the journal editor, the team has refined the original plan, eventually arriving at a method that everyone agrees is a good test of the hypothesis. If it finds no effect, said Strack, ‘that would be a strong argument that maybe the facial feedback hypothesis is not true.’”

“An early pilot of the Many Smiles study…suggested that smiling can affect feelings of happiness. Later this year, all the collaborators will kick into gear to see if the pilot’s findings can be repeated across 21 labs in 19 countries. If they find the same results, will that be enough to convince even the skeptics that it’s not just a fluke?”

“Well … maybe. A study like Wagenmakers’s sounds, in principle, like enough to lay a scientific question to rest, but it wasn’t. A study like Coles’s sounds like it could be definitive too, but it probably won’t be. Even Big Science can’t make science simple.”

To read the article, click here.