But is there a motive to the sweet expression?
In the Sept. 23 issue of PLOS ONE, a team of computer scientists, roboticists and developmental psychologists confirm what most parents already suspect: when babies smile, they do so with a purpose–to make the person they interact with smile in return.
Do infants desire to influence others in mutually beneficial ways? Appears so, according to this research. Call it an infant power play.
The scientists conducting the study used a learning, robotic toddler that was developed to mimic the mannerisms and characteristics of a real, human toddler. The study is part of an effort funded by the National Science Foundation to use robots to better understand human development.
It gives developmental psychologists a tool for studying non-verbal children and adults, such as those with autism, researchers said.
“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 the University of California, San Diego, and one of the study’s authors. “But proving this is difficult.”
Researchers used data from a previous study, in which 13 mothers and their children had their facial expressions monitored, including when and how often they smiled. The control theory data analysis found that 11 out of the 13 babies in the study showed clear signs of intentional smiling.
So the researchers developed a program that mimicked the babies’ actions and transferred it onto Diego San, a toddler-like robot that Movellan’s team had used for similar studies in the past.
Upon interacting with Diego San, 32 undergraduates from UC San Diego discovered that in fact, there was a motive behind the robots smiling. Diego San smiled back every time one of the undergraduates smiled. “What makes our study unique is that previous approaches to studying infant-parent interaction essentially describe patterns,” said Messinger. “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.”