Jun 28, 2017

Reverse-engineering a winning smile

Researchers from the University of Minnesota have figured out the features of a winning smile.

  • It's a balance of the mouth's angle, smile width, how many teeth are visible and symmetry. Best bet: showing just a little bit of teeth.
  • Smiles that form slightly asymmetrically were seen as more "genuine" and "pleasant" — to a point. If it happens relatively slowly (longer than 125 milliseconds), the crooked smile just starts to get "creepy."

Why the findings matter:

  • They guide surgeries to reanimate someone's face after a stroke, says author Sofia Lyford-Pike, a facial plastic and reconstructive surgeon at the University of Minnesota. (People who are unable to smile effectively are at increased risk for depression.)
  • It could inform computer graphics.
  • More broadly, the work may help to understand how individual differences in facial expressions can lead to differences in how people perceive threats, trustworthiness and other socially relevant cues, something researchers have long studied.

What they did: The researchers created 3D computer animated faces with slightly different smiles constructed from combinations of different angles of the mouth, varying extents of the smile, how much teeth were showing and how symmetrically the smile formed on the face. 802 people were then asked to rate 250 millisecond-long video clips of the smiles forming for their effectiveness, how genuine they seemed, whether they were "pleasant" or "creepy," and what emotion they thought the smile conveyed. The best-rated smiles have lips angled between 13 and 17 degrees and extend between 55% and 62% of the distance between the eye's pupils.

Two smiles with a combination of (a) smaller and (b) larger mouth angle-smile width combination. Increasing how much teeth are visible led to a more favorable rating of the smile in (b) and a worse rating for (a).Helwig et al. University of Minnesota

Limitation: The study only modeled the mouth. Previous work has found the eyes influence people's perceptions but the study shows the mouth can transmit a lot of information on its own, says Lyford-Pike.

What's next: Determining whether the results translate to spontaneous smiles of different, real people, is a key question, says Aleix Martinez, a cognitive scientist and professor of electrical and computer engineering at Ohio State University. Martinez asks: "Can you predict a person's success (personal, profession) on the "niceness" of their smiles?"

Go deeper

Situational awareness

Photo: Brett Carlsen/Getty Images

Catch up on today's biggest news:

  1. Mike Bloomberg offers to release women from 3 NDAs
  2. Wells Fargo to pay $3 billion to settle consumer abuse charges
  3. Bloomberg campaign says Tennessee vandalism "echoes language" from Bernie supporters
  4. Scoop: New White House personnel chief tells Cabinet liaisons to target Never Trumpers
  5. Nearly half of Republicans support pardoning Roger Stone

Wells Fargo agrees to pay $3 billion to settle consumer abuse charges

Clients use an ATM at a Wells Fargo Bank in Los Angeles, Calif. Photo: Ronen Tivony/SOPA Images/LightRocket via Getty Images

Wells Fargo agreed to a pay a combined $3 billion to the Justice Department and the Securities and Exchange Commission on Friday for opening millions of fake customer accounts between 2002 and 2016, the SEC said in a press release.

The big picture: The fine "is among the largest corporate penalties reached during the Trump administration," the Washington Post reports.

Bloomberg offers to release women from 3 nondisclosure agreements

Mike Bloomberg. Photo: Brett Carlsen/Getty Images

Mike Bloomberg said Friday his company will release women identified to have signed three nondisclosure agreements so they can publicly discuss their allegations against him if they wish.

Why it matters, via Axios' Margaret Talev: Bloomberg’s shift in policy toward NDAs comes as he tries to stanch his loss of female support after the Las Vegas debate. It is an effort to separate the total number of harassment and culture complaints at the large company from those directed at him personally. That could reframe the criticism against him, but also protect the company from legal fallout if all past NDAs were placed in jeopardy.