Robot Teaches Us Why Babies Smile So Much (VIDEO)

First Posted: Sep 25, 2015 04:14 PM EDT

Why do babies smile so much? To get smiles in return, of course.

Researchers at the University of California, San Diego found that babies are effortlessly flashing their adorable little smiles in the hopes of getting a smile or two back in return. The findings are published in the journal PLOS ONE.

"If you've ever interacted with babies, you suspect that they're up to something when they're smiling. They're not just smiling randomly," said Javier Movellan, a research scientist in the Machine Perception Laboratory at UC, San Diego, and one of the study's authors via a press release. "But proving this is difficult."

In this recent study, researchers combined developmental psychology, computer science and robotics to get a better understanding of baby's smiling. They used data from a previous study that observed face-to-face interactions of 13 pairs of mothers with their babies, all of whom were under four months. The study looked at when and how often both parties smiled. Then, the researchers reverse-engineered the findings, showing that babies use a sophisticated timing mechanism in order to get the most smiles back possible, meanwhile exhausting as little energy as possible.

Afterward, the researchers sought the help of 32 San Diego graduates to interact with "Diego San," a robot programmed to mimic four different baby behaviors found during the previous study. The students behaved as the mothers when involved in robot interaction, during three-minute sessions in which one of the four different behaviors was displayed. The findings revealed that the robot got the babies to smile just about as much as they possibly could, confirming the previous findings that babies use timed smiles to elicit more smiles from people.

"What makes our study unique is that previous approaches to studying infant-parent interaction essentially describe patterns," said Javier Movellan, a research scientist and study author, in a news release. "But we couldn't say what the mother or infant is trying to obtain in the interaction. Here we find that infants have their own goals in the interaction, even before four months of age."

Want to see the robot in action? Check out this video, courtesy of YouTube.