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Cognitive Development: Infants and Toddlers

Infants and toddlers usually follow predictable patterns in how they grow and learn. This lesson will help you understand typical cognitive development, or how infants and toddlers develop thinking skills. You will learn about developmental milestones and what to do if you are concerned about a child’s development.

  • Identify typical cognitive developmental milestones from birth to age three.
  • Demonstrate developmentally appropriate expectations.
  • Discuss what to do if you are concerned about an infant’s or toddler’s development.



Infants and toddlers are born ready to learn. They learn through cuddling with a caregiver, listening to language, experimenting with sounds, moving their bodies, reaching for objects, tasting foods, and exploring their environments. Their brains go through amazing changes during the first three years of life. This lesson will highlight cognitive developmental milestones for infants and toddlers.


Infants’ and toddlers’ thinking skills grow as they interact with the world and people around them. The key to healthy brain development is through nurturing and responsive care for a child’s body and mind. As you learned in the first lesson, how the brain grows is strongly influenced by a child’s early experiences. Therefore, supporting a child’s cognitive development with consistent, nurturing experiences and interactions is critical for brain growth. As infants and toddlers develop, they begin to understand and predict how things work: they open and close a cabinet door over and over, they fill and dump a cup of water in the water table, they bang a spoon on a high chair to hear the sound.

Watching an infant or toddler make new discoveries is exciting. Think of how amazing it is the first time an infant stacks blocks (and knocks them down) or the first time a toddler pretends to “read” a book to you. The chart below highlights infant and toddler cognitive development. Keep in mind that individual differences exist when it comes to the specific age at which infants and toddlers meet these milestones and that each infant and toddler is unique. As you may have already learned in other courses, milestones provide a guide for when to expect certain skills or behaviors to emerge. Think of milestones as guidelines to help you understand and identify typical patterns of growth and development, or to help you know when and what to look for as young children mature. As an infant and toddler caregiver, you can use this information, what you learn from families, and your own knowledge in the interactions, experiences, and environments you create for infants and toddlers.

Chart: Cognitive Developmental Milestones

2 months
  • Follows objects with eyes and recognizes people at a distance as they move
  • Looks at objects for several seconds
  • Waves arms at dangling objects dangled in front of them
4 months
  • Opens mouth at the sight of breast or bottle
  • Looks at hands with interest
  • Looks at objects placed in hand or in front of them
6 months
  • Brings things to mouth to explore them
  • Reaches to grab objects
  • Closes lips to show disinterest in more food
  • Plays by banging objects on the tables or ground
9 months
  • Looks for objects when places out of sight
  • Bangs two objects together
  • Picks up toys one in each hand
12 months
  • Puts objects inside a container
  • Looks for objects they see you hide
  • Uses index (pointer) finger to poke and try to get objects out
15 months
  • Starts to use things correctly (like cups, phones, books)
  • Stack at least small two objects
  • Scribbles back and forth on paper
  • Dumps objects out by turning containers upside down
18 months
  • Shows interest in copying simple chores like sweeping or wiping the table
  • Plays with toys in a simple way (playing in their intended way, pushing a toy car)
  • Points to show something of interest
  • Can follow one-step verbal commands without any gestures; for example, sits when you say “sit down”
  • Scribbles on own
24 months
  • Holds something in one hand while using the other hand
  • Attempts to use switches knobs and buttons on a toy
  • Plays with more than one toy at the same time
  • Begins putting items where they belong, like toys on the shelf
  • Stacks 4 objects
30 months
  • Plays make believe with dolls, animals, and people
  • Shows skills in simple problem-solving skills like standing on a small stool to reach something
  • Follows two step directions like, “Pick up your shoes and put them in the closet”
  • Knows at least one color
  • Tells you what they drew after drawing or scribbling a picture
36 months
  • Copies a circle with a pencil or crayon
  • Avoids touching hot objects after a warning
  • Can work toys with buttons, levers, and moving parts
  • Builds towers of more than 6 blocks

Source: Centers for Disease Control and Prevention (2021). Developmental Milestones. .

It is important to know that how infants and toddlers are assigned to classrooms may not reflect the age spans listed above. There are programs that regroup children every six months and those that use multi-age or family-style groupings, which keep children and their teachers together for a longer period of time. It is best practice to minimize the number of times infants and toddlers must transition from one age group to the next.

Cognitive development is a unique process specific to each infant, toddler, and family. Many factors influence cognitive development, including genes, events during pregnancy or birth, and aspects of the child’s environment. A family may wonder about their young child’s cognitive development and feel uncertain about what they are observing and what to expect. As an infant and toddler caregiver, take the opportunity to first learn from a family, and then to consider offering additional developmental information, including possible warning signs. The Kids Included Together website,, can be a valuable resource for you, as can the developmental milestones and Act Early information located on the Centers for Disease Control and Prevention website, The table below also highlights some possible warning signs for infants and toddler development:

Possible Warning Signs for Cognitive Development Issues for Infants and Toddlers

Young Infants
  • Does not watch things as they move
  • Does not bring things to mouth
Mobile Infants
  • Does not try to get things that are in reach
  • Has difficulty getting things to mouth
  • Does not play any games involving back-and-forth play (e.g., peek-a-boo)
  • Does not seem to recognize familiar people
  • Does not look where you point
  • Does not transfer toys from one hand to another
  • Does not learn gestures like waving or shaking head
  • Loses skills they once had
  • Does not search for things they see you hide
  • Does not copy others
  • Does not point to show things to others
  • Does not know what to do with common things, like a brush, phone, spoon
  • Does not follow simple directions
  • Does not play pretend or make-believe (at 3 years)
  • Loses skills they once had

If you are concerned about a child’s development, talk with your trainer so that you can work together to talk with parents about your observations. This may be a difficult conversation, but it can help to ensure that the child is receiving the supports that they need to be successful. With the guidance of your trainer and program manager, you can share information with families about typical child development and let them know you are available to talk. If your program provides developmental screening tools, these can help you start a conversation about your concerns.

Ultimately, if families are concerned about their child’s development, they should talk to their child’s pediatrician about their concerns. Pediatricians can perform developmental screenings and possibly refer the child to specialists. Families should also contact their statewide early intervention program (for children under age 3). These programs will provide a free evaluation of the child’s development. This can help the child get the services and help he or she needs. This video, developed by the U.S. Centers for Disease Control and Prevention, offers tips for identifying and acting on suspected developmental delays:


Just as children’s bodies grow throughout infancy and toddlerhood, their brains are growing, too. You will see major changes in a child’s thinking skills between birth and 3 years of age. Watch this video to learn about milestones for infants and toddlers.  

Cognitive Development for Infants and Toddlers

Watch the range of cognitive development from birth to age three.


Understanding developmental milestones will help you know what kinds of learning experiences to plan in your classroom. Based on your knowledge of development, you can ensure that your interactions and activities are appropriate for individual children. Remember, milestones are markers that let us know a child is growing in an optimal way. As an infant toddler caregiver, do the following to support developmental milestones:

  • Give infants and toddlers the safe space they need for movement and discovery (areas for climbing, crawling, pulling up, etc.)
  • Offer safe, developmentally appropriate materials for exploring (foam blocks, board books, musical instruments, containers for sorting and filling, etc.)
  • Provide a consistent, nurturing relationship with each infant and toddler. 
  • Read about the stages of development, especially for the ages of the children you serve.
  • Post developmental milestone charts for reference and visual reminders.
  • Recognize that children need different things from you as they move through the developmental stages.
  • Observe children and document their progress on a regular basis to determine where they are developmentally so you can both support and challenge their emerging skills.
  • Remember that children are unique and progress at different rates and that one area of development may take longer than other areas.
  • Consult with your administrator, trainer, or coach if you feel that there might be a concern with how a child is developing.


Observing infants and toddlers can help you see where they are developmentally, which is important as you plan learning experiences for them. Download and complete the Stages of Development Observation activity. Share with your administrator, trainer, or coach.


It is important to understand and remember developmental milestones. Download and review the Cognitive Development Milestones poster and use it as a reference in your work. You may also choose to share the poster with families. 


Cognitive skills:
The mental skills or behaviors that help children access information, solve problems, reason, and draw conclusions
Developmental delay:
This may be suspected when children do not meet developmental milestones at the expected times; delays can occur in any area of development
Developmental milestones:
A set of skills or behaviors that most children can do at a certain age range
Developmental screening:
A tool used to help identify children who are not developing as expected and who may need supports; screening can be completed by pediatricians, teachers, or others who know both the child and child development well


True or false? Cognitive developmental milestones let you know when certain skills and behaviors will develop.
Which of the following is a possible warning sign concerning an infant’s or toddler’s cognitive development?
Your coworker asks how they can support developmental milestones in their classroom. You respond by saying…
References & Resources

Centers for Disease Control and Prevention. (2021). Developmental Milestones.

Early Childhood Learning & Knowledge Center. (n.d.).

Eileen Allen, K., & Edwards Cowdery, G. (2014). The Exceptional Child: Inclusion in early childhood education (8th ed.). Belmont, CA: Wadsworth Publishing.

National Association for the Education of Young Children. (n.d.).

Paul H. Brookes Publishing Co. Inc. (2022). Ages and stages questionnaire (ASQ).

Track Your Child’s Developmental Milestones. (2011). [Brochure]. Missouri First Steps, Early Intervention.

Zero to Three. (2021).