Thinking, making new connections, and discovering the world

In the first year of life wonderful and dramatic things happen. The baby usually triples her birth weight; she moves from being totally dependent to crawling and walking. Well before they use spoken language, infants are observing and making connections about what's going on around them. They are soon able to communicate, to interact with others, and to think about their surroundings. Each area of growth occurs in tandem with others- e.g., social and emotional with motor, communication and thinking.

Milestones are flexible; they are approximate times when certain abilities are observable. There is no strict timetable for acquiring abilities or confronting different challenges, and there's a wide range for what's considered normal. Every child grows and adjusts to the world at his or her own pace. This article outlines the development of cognitive abilities.

First Year Milestones

The newborn explores the world by mouthing objects; by one year he expands his exploratory techniques by imitating actions, manipulating objects and planning two-step strategies to get what he wants. He is establishing the base on which to build increasingly complex cognitive accomplishments.

Between birth to 4 months the child

  • turns his head to look towards sound
  • follows moving toys with eyes
  • recognizes family members
  • explores new objects by mouthing
  • makes simple associations, e.g. if he cries he gets picked up memory: starts to expect feedings at regular intervals; distinguishes key people in his life; may single out mother in a group of people

By 5-8 months the child

  • seeks stimulation
  • explores by touching, shaking and tasting objects
  • explores his own body with hands and mouth
  • discovers that objects exist even when they're out of sight; watches and looks for hidden toy
  • pulls string to get toy out of reach
  • explores cause and effect by banging, rattling and dropping objects
  • memory: may anticipate a whole object after seeing a piece of it; observes comings and goings of others; remembers sequences such a jack-in-the-box that jumps up at the end of a song

By 9-12 months the child

  • holds 3 toys at the same time
  • finds a hidden toy
  • uses an object as a container
  • imitates actions
  • holds one toy and explores with the other hand
  • starts linking meanings to gestures, shaking his head no and waving bye-bye
  • memory: notices when someone leaves room and anticipates their return
  • categorizes objects (thinks about similarities and differences), and develops symbolic thought.
  • "thinks" about things in very simple ways without actually needing them to be present and visible, an ability which leads the way to the development and use of imagination

Second Year Milestones

At 16 months the child

  • uses simple puzzles or formboards
  • places an object into a bottle and dump it out
  • scribbles spontaneously
  • points to body parts

At 21 months the child

  • knows what to do with common objects, such as a hammer, etc. and knows their purpose
  • plays imaginatively; pretend to cook, dust, wash dishes, play "mommy" or "daddy" etc.
  • points to four or more body parts
  • puts together a simple two-piece puzzle
  • uses chairs to reach things

By 2 years the child

  • categorizes faces, animals, and birds according to their individual characteristics
  • draws a circle, line or V after watching
  • looks for ways to work new toys
  • names pictures of familiar objects
  • nests boxes, cups or stacking rings
  • puts together simple puzzles
  • shows a basic sense of time when told "later," "soon," or "not now"
  • understands consequences of actions-physical: if I push a button, the light goes on, and behavioral: if I cry, my mother will come
  • understands the concept of one

By 3 years the child

  • draws a person
  • builds with blocks in all directions with the intent of making towers, trains, buildings, etc.
  • understands in, out, in front of, under, over, etc.
  • turns pages of a book one by one
  • makes inferences about new members of a category
  • enjoys displaying his new knowledge

The thinking of children at this age is still tied to the concrete; they are not yet aware of concepts such as change over time and have little idea of the true meaning of killing or dying. At times they may confuse fact and fantasy.

The Three-to-Four Year Milestones

By 4 years the child

  • learns to sort objects by shape, color and size; similarities and differences
  • counts four objects
  • a square and some capital letters
  • draws a human figure with a head, body, arms, legs and perhaps five fingers
  • names three coins
  • knows his age
  • knows about the seasons and related activities
  • knows at least four colors

By five years the child

  • understands a whole object or concept, but not always the relationship of the parts to the whole
  • uses simple reasoning; begin to understand cause-and-effect relationships
  • memorizes things but does not yet have strategies such as rehearsing lists
  • traces numbers and capital letters; may write some numbers and letters on her own
  • counts things

During the first five years, development proceeds at a pace exceeding that of any other phase of life. During this time the brain undergoes its most dramatic growth, and children rapidly develop the cognitive capacity that enables them to become intellectually curious and creative thinkers.

About the NYU Child Study Center

The New York University Child Study Center is dedicated to increasing the awareness of child and adolescent psychiatric disorders and improving the research necessary to advance the prevention, identification, and treatment of these disorders on a national scale. The Center offers expert psychiatric services for children, adolescents, young adults, and families with emphasis on early diagnosis and intervention. The Center's mission is to bridge the gap between science and practice, integrating the finest research with patient care and state-of-the-art training utilizing the resources of the New York University School of Medicine. The Child Study Center was founded in 1997 and established as the Department of Child and Adolescent Psychiatry within the NYU School of Medicine in 2006. For more information, please call us at (212) 263-6622 or visit us at