Browse by age
3 to 5 years
Children vary a lot. These are milestones that many children reach somewhere in this window.
Thinking and learning
- Knowing what "three" means
Children learn what "one", "two" and "three" mean one at a time, often months apart. In US studies, children who knew up to "three" were about 3½ on average. Understanding how counting tells you "how many" comes next.
Typical age: about 3½ years. Studies haven't yet measured how widely the ages spread. - Understanding that people can believe something untrue
Most children come to understand that someone can believe something that isn't true somewhere between about 3 and 6 years, often around 4 to 5. In five very different countries, about half of 4-year-olds and most 5-year-olds understood it.
Everyday skills
- Staying dry at night
Staying dry at night usually comes after being dry during the day, often between about 3 and 4 years. Wetting the bed sometimes is still common at school age: about 3 in 10 children at 4½ and about 1 in 10 at 9½.
Typical age: about 3 to 4 years. Studies haven't yet measured how widely the ages spread. - Giving up daytime naps
Most children stop napping somewhere between about 3 and 5 years. Very few stop before 2, about a third have stopped by 3, more than half by 4 and about 8 in 10 by 5, though studies vary a lot.