Parents love nothing more than to gaze lovingly into their baby’s eyes while smiling broadly and burbling soft baby talk. That’s a good thing. Looking at a baby (and letting them look back) is developmentally important as they begin to understand the fundamentals of communication. But it’s also just as important for a parent to look away from their baby and out at the world. Because not only are babies interested in a parent’s face, they’re interested in what a parent is looking at, which helps them catalog all the things they see.
“In order to acquire words, you have to learn there’s a word out there called ‘cup,’ but then you now have to figure out which of the objects ‘cup’ refers to,” explains Dr. Celeste Kidd of the University of Rochester Kid Lab. This is known as the “mapping problem,” and Kidd notes that babies have an ingenious way to solve it. “We know that one of the primary keys that infants use to solve that problem is an adult’s eye gaze.”
Essentially, when a baby looks where an adult is looking and the adult uses a word to label what they’re looking at, the baby is able to map, or save, the association in their brain. In this way, they begin building a vocabulary. The act is called “shared gaze” and babies who exhibit a shared gaze ability early in the first year are found to understand far more words than babies who exhibit the ability later. That said, most babies are able to share an adult’s gaze by eight months of age.
Shared gaze has some important implications for parents in the age of cellphones and tablets, particularly when it comes to the phenomenon known as “phubbing,” a portmanteau of phone and snubbing. Because when a parent is beside their baby and their gaze is constantly on their device, their baby can’t share their gaze. It follows that there would be no mapping during this time. Shared gaze also has implications for the importance of reading picture books to babies. That’s because studies have shown that an infant can map objects that are in books too. “When you read books to your kids you get to jointly attend to objects you wouldn’t normally encounter in the real world,” says Kidd. “When you look at a giraffe in a book and point to it and say ‘giraffe’, it’s very clear what giraffe represents in the world.”
But Kidd notes that there are more benefits from a parent’s conscious effort to increase gaze sharing. Most notably, it requires parent and child to interact. “Babies love being attended to,” she says. “Your kid will be happier.”
There’s also a huge caveat for parents to internalize once they’ve discovered the strange wonder of gaze sharing: Just because a baby is developing their vocabulary doesn’t mean they’re somehow going to be better for it in the future.
“Everybody, eventually, acquires all the words they need to,” explains Kidd. “It’s not clear how important early acquisition of words is. Kids talk at very different rates. I would caution parents to not be too worried.”