Cognitive Development

By 9 months, most children:

• Pause or stop when an adult says “stop” or tells them not to do something
• Demonstrate caution around new or unusual people or events
• Explore objects by holding, mouthing, dropping, etc.

By 18 months, most children:

• Inhibit themselves from reaching for a visible but inaccessible object or reward (e.g., a toy on the other side of a window or out of reach)
• Attend to a short, familiar storybook but may not want to follow the book page by page

By 24 months, most children:

• Have a general understanding of the passing of time and the meaning of phrases like “not now” and “after lunch”
• Comply with simple two-part requests that involve waiting (e.g., “Eat your breakfast and then we’ll play with the blocks.”)

By 36 months, most children:

• Wait to be handed a desired object
• Attend to specific features of objects and identify elements within a complex figure (e.g., looking at a picture of a farmyard and pointing to and naming the figures of a horse, a duck, a cat, etc.)
• Follow adult directions when given simple guidance
• Focus on topics or materials of interest despite distractions (e.g., can dump out and solve a favorite puzzle, even with other children playing in the background)

By 48 months, most children:

• With adult support, avoid imitating the negative behavior of another child
• With adult reminders, wait to communicate information in a group
• Focus on increasingly complex topics for longer periods of time
• Return to complete a task if interrupted
• Count only those objects in a group that have a specific attribute (e.g., all of the red cars in a picture)
• Solve simple arithmetic problems
• Build block buildings and include such structural features as arches and ramps

By 60 months, most children:

• Without adult reminders, wait to communicate information in a group
• Maintain focus on a project for a sustained period of time and over several days
• Return with focus to an activity or project after having been away from it for a period of time
• Demonstrate an awareness of important activities that are “coming up” or “in the near future” (e.g., keeping track of the days until a birthday or vacation trip) as a strategy to control excitement
• Combine shapes into patterns that make new shapes or complete puzzles (e.g., rearranging a collection of circles and variously sized rectangles to make the image of a person)
• Build complex block buildings, intentionally maintaining such features as symmetry