Intellectual development includes thinking, problem solving, understanding concepts, processing information, and overall intelligence. As a child develops cognitively, she is able to navigate her surroundings and the world.

Behavioral development is reflected by children’s actions in or responses to their environment. These responses may be voluntary or involuntary, conscious or unconscious. Play and interactions with other people and objects within the environment are important in cognitive and behavioral development.

What follows are typical milestones for cognitive and behavioral development in young children, as well as warning signs of possible delays. There is a wide range of typical development. However, follow up with a pediatrician if your child shows signs of delays.

Birth to Three Months

• Prefers looking at faces
• Begins to imitate facial gestures
• Shows anticipation of event that occur regularly in everyday care
• Begins to relate what he sees with what he touches

• Reaches and attempts to get objects out of reach
• Retrieves an object that is partially hidden under a cover
• Pulls a cloth from a caregiver’s face and from own face
• Plays alone with toys, progressing with shaking, rattling, and banging objects

• Develops object permanence
• Searches for hidden objects
• Responds to simple commands; knows own name and understands “no”
• Imitates gestures and actions
• Looks at the correct picture when it is named
• Begins to use objects appropriately, such as drinking from a cup, holding up a phone receiver to the ear, or brushing hair
• Explores toys with a variety of skills, such as throwing, dropping, banging, and shaking objects

• Likes simple games, such as Peek-a-boo
• Experiences separation and stranger anxiety; clings to parents and begins to fear strangers

• Learns mainly through trial and error
• Begins to notice other children
• Enjoys playing with adults and begins to play and talk alone
• Likes picture books and will pay attention to a picture book for at least five minutes
• Begins to recognize parts of the body when asked

• Finds a hidden object under two to three covers
• Recognizes body parts, familiar people, and objects such as clothing
• Has increased attention span
• Develops increasing independence

• Puts together simple two- to four-piece puzzles
• Places correct shape in shape sorter
• Begins matching and sorting objects and colors
• Shows defiant behavior
• Has increasing separation anxiety at age two, which then fades
• Imitates behaviors of other adults and older children

• Understands how mechanical toys work
• Sorts objects by size
• Sorts objects by primary colors and shape
• Starts to use more reasoning skills as well as trial and error
• Engages in pretend play with dolls or toys
• Matches objects to pictures
• Understands the concept of two
• Uses imaginative play with people, dolls, etc.

• Sorts items into categories
• Completes simple interlocking puzzles
• Begins to understand the concept of time
• Questions parents
• Becomes more elaborate with imaginary play
• Increases aggressive behavior