How many participants do infants represent when they view events in the world?

In order to learn the meaning of a new verb, like take, children need to decide what kind of event in the world it labels, and whether that event tends to have one, two, or more core “participants.” Here, we asked how many participants infants readily perceive when viewing events in the world, independent of language. This will help us understand how they expect language to relate to these event representations.

We showed 10-month-olds silent scenes in which a girl picks up a truck from a table and moves it towards herself, while a boy sits idly beside her. Once they habituated (got bored with) these scenes, we then made a subtle change. One group of infants saw a scene in which the girl picks up the truck in the same manner as before, but the boy is now holding onto it, and the girl lifts it out of his grasp. A second group of infants saw a scene in which the boy is still uninvolved, but the girl slides the truck towards herself across the table, instead of lifting it. We hypothesized that infants would view the first type of change as a change in the number of participants, going from a 2-participant “picking-up” event involving just the girl and the truck, to a 3-participant “taking” event involving the girl, the truck, and the boy. We hypothesized that the second type of change would be viewed as a change in the manner of motion, but not in participant number. Consistent with our predictions, we found that infants recovered attention more when they saw the participant change than when they saw the manner of motion change, indicating that they perceived the participant change as more noteworthy— it was a bigger change conceptually. This tells us that they viewed the “taking” scene under a 3-participant concept, in which the girl, the truck, and the boy all played important roles.