A main source for the ages
One, two, three, four, nothing more: An investigation of the conceptual sources of the verbal counting principles
Mathieu Le Corre, Susan E. Carey · 2007 · Cognition
- Children
- About 180 children in two studies
- Where
- The United States
- Ages
- 2 to 5½ years
- How
- Researchers asked children to give a puppet a number of toys
- What it found
- Children learned "one", then "two", then "three" before understanding how counting works. Children who knew up to "three" were about 3½ on average. Most could already recite the numbers to eight.
- Limits
- Mostly families from one country. These are average ages of children at each step, not the age when half of children get there.