Infants as young as 8 months use change to count objects.

How do babies figure out how many things are hidden in front of them? Normally, we know two items exist if we see them at the same time. If a screen hides them, babies must use clues like what the items look like. Before 12 months, babies struggle to tell how many objects are hidden just by seeing different types, like a duck and a truck. They also fail when items only differ by color. Researchers tested if babies understand the abstract idea of change itself. They showed infants a screen where two objects came out one after the other. One object changed continuously, while the other stayed static. Babies successfully used this difference to figure out that two separate objects were present. This was not just because the changing object caught their eye. By 8 months, infants already understand change as a core property of the world.

Why it matters

This matters because it reveals that even before they can talk, babies already grasp change as a core property of the world. It challenges the idea that infants only track objects by static features like color or shape. Instead, they can use dynamic information—whether something changes or stays the same—to figure out how many things are in front of them.

Questions answered