Imagine spending a beautiful day at the lake with your little one. As an English speaker, you might delight in sharing descriptions of the deep blue water, green grass, and light blue sky in front of you. But speakers of Berinmo, an indigenous language of Papua New Guinea, have a single term for the colors we describe as blues and greens. They would instead describe the water, grass, and sky as a single hue, “nol.”
This compelling cross-cultural evidence leaves little doubt that the categories we form bear the imprint of our language. But how early in life does naming shape the categories we perceive?
To answer this question, researchers in our lab created a continuum of colorful cartoon-like creatures. First, in a learning phase, 9-month-old infants had an opportunity to observe several of these creatures, presented in random order: Each appeared at the center of the screen, moved in one direction or another, and then disappeared. Creatures from one end of the continuum moved to the left, and those from the other end moved to the right. What varied was how the creatures were named. Infants in the one-name condition heard the same novel word applied to all objects along the entire continuum; those in the two-name condition heard one name for objects from one end and a second name for objects from the other. Next, in a test phase, all infants viewed new creatures from the same continuum.
We were interested in whether infants would anticipate the side to which the test objects would move, and whether their expectations varied as a function of hearing one name versus two.
The results were clear: infants in the two-name condition discerned two categories and, therefore, correctly anticipated the likely location of the test objects, whether these were close to the poles or to the center of the continuum.
In sharp contrast, infants in the one-name condition formed a single overarching category and therefore searched for new test objects at either location.
These results constitute the first evidence that for infants as young as 9 months of age, naming not only shapes the number of categories they impose along a perceptual continuum but also highlights the joints or boundaries between them.
“Naming influences 9-month-olds’ identification of discrete categories along a perceptual continuum” will be published in the journal Cognition.