As you push your toddler down the sidewalk in her stroller, a man walks by with a French Bulldog. “Look, a dog,” you say to her. A minute later, you pass a German Shepherd eyeing you from the first-floor window of a house. “Look, a dog,” you say. Over many such instances, the label you provide helps your daughter recognize that these very distinct individuals all share commonalities that comprise the category “dog.” We know that seeing category examples while hearing a consistent label helps children form categories, but even the most vigilant parent does not label every single instance of a dog that her child sees. Perhaps one morning your daughter is flipping through a copy of Clifford the Big Red Dog as you get ready for work, or one afternoon you and your partner chat about the Cubs game in the park as your daughter watches a poodle and its owner trot past.
So what is the relationship between seeing labeled and unlabeled examples of a new category, and how does that relationship impact a child’s ability to learn the category? This is the question we’ve been asking recently in our lab. To answer it, one of our researchers, Sandy LaTourrette, designed a study mimicking a sped-up version of the same categorization process that takes place in the real world. Knowing that our savvy 2-year-old study participants are very familiar with dogs, we designed a new category of whimsical creatures that fall along a gradient of colors and shapes (two examples of creatures from the same category are below).
The children in our study were divided into four different groups. First, children in every group saw six different members of the same category for three seconds each. What differed was the timing and frequency of labeling. Children in one group had all six examples labeled for them (e.g., “Look at the modi!”). In another group, none of the examples were labeled. In a third group, the first two examples were labeled and then four were unlabeled. In the final group, the first four examples were unlabeled and the last two were labeled. As you might expect, children handily learned the new category in the group where every creature was labeled but the children in the group with only unlabeled examples did not learn the category. Your child would learn the category “dog” much more quickly if every dog she saw were labeled for her than if none were; this is no surprise.
But what about the group where two of the creatures were labeled at the beginning of the series and the group where two were labeled at the end? Our researchers were most interested in these groups. Interestingly, children who received two labels at the beginning performed just as well as the children in the group who heard a label every single time. On the other hand, the children who heard two labels at the end failed to form the category. This suggests that after children have seen just a couple of labeled examples, they learn just as well from unlabeled examples as labeled ones.
So what’s the take-home for busy parents? Engaging your little language learner does help them learn about the world, but don’t feel anxious about naming every single item they see at all times—after a “look at the dog” or two, the invitation to form a category has been extended, and our eager young language learners are ready to start picking things up on their own.
Researcher Sandy LaTourrette’s paper describing the above research was awarded the Jean Berko Gleason Award for top student paper at this year’s Boston University Conference on Language Development.