Babies Time Their Adorable Smiles to Manipulate Adults

By timing their grins, babies can get adults to grin

Baby smile
What a cute little schemer Kaori Ando/Corbis

A cute, cuddly baby grins seemingly without guile: eyes crinkle with the merriment of a true smile. But it turns out that these young ones are only smiling to get adults to smile back. What to us appears to be an adorable chuckle, is really a feat of manipulation with some expert timing, researchers have found, reports Gary Robbins for The San Diego Union-Tribune

"Babies are very goal-oriented," study leader Javier Movellan, a psychologist at the University of California, San Diego, tells Robbins. The research team found that by timing their smile precisely, babies can elicit maximum smiles with little effort on their part.

However no real babies were harmed in learning their secret. The team used a "toddler" robot named Diego-San to test the smile timing. In tests with undergraduate students, randomly-timed smiles didn’t elicit the attention that perfectly timed smiles did. The researchers figured out the proper programming for the little robot using data from previous studies that examined interactions between mothers and their babies. 

The little tykes could time how long they made eye contact and how quickly their lips turned up in a smile by the time they were four months old, the researchers knew. Babies know how to get the adult to spend the most time smiling, sometimes even when the baby itself isn’t, the team reports in PLOS One

The researchers didn’t speculate on the purpose of getting adults to smile, but babies helplessness already suggests the need to maximize good feelings in their caregivers. The team does mention that their finding might help psychologists come up with new tests to track children’s development, especially with disorders such as autism. 

Babies’ Machiavellian smiles might not be all that bad however. Other research shows that the simple act of grinning can reduce stress. Of course, babies probably like that result too.

Get the latest stories in your inbox every weekday.