Skip to main content

Cognitive Development: An Introduction

The first three years of life are an amazing time for the human brain. When you support the developing brain, you are building a strong foundation for future school and life success. This lesson will introduce you to important concepts about how the brain develops in infants and toddlers. It will end with suggestions about what you can do to help make sure all children meet their potential.

  • Define cognitive development.
  • Describe what cognitive development looks like during the infant and toddler years.
  • Identify ways you can support cognitive development.



As an adult, you have already developed many of the thinking skills that help you understand the world around you. Think about the skills and strategies that have helped you succeed at daily tasks like: 

  • Reading and following the recipe for a new meal
  • Finding a different way home when traffic is heavy
  • Estimating the amount of material you will need for a home improvement project
  • Finishing a book and discussing it with friends
  • Filling out a job application
  • Fixing a leaking faucet or pipe
  • Budgeting for groceries and other essentials

What thinking skills have helped you with these kinds of tasks? Reading, writing, measuring, calculating, problem-solving, hypothesis testing, comprehending, and recalling facts are all essential for many of the tasks you accomplish every day. You started developing those skills as a child, and they continue to develop as you encounter new situations as an adult.

The infants and toddlers you care for are just beginning to explore the world around them as their brains develop in amazing ways. The work you do every day lays the foundation for these infants and toddlers to develop the thinking skills they need to be successful in school and life. This course will help you understand how your work contributes to the development of thinking skills in the infants and toddlers you serve.

What is Cognitive Development?

Cognitive development is all about learning and reasoning, including the development of memory, symbolic thought, and problem-solving skills. When a child imitates an adult, makes a “ruff” sound when they see a dog, or smiles upon hearing a familiar voice, that is cognitive development in action. Take a moment to consider other examples of cognitive development that you have observed with infants and toddlers. 

According to Dodge, Colker, and Heroman (2010), “Cognitive development refers to the mind and how it works. It involves how children think, how they see their world, and how they use what they learn.” Who children become has everything to do with the experiences they have early in their lives, the experiences they have while they are in your care. Outside of their families, you might be the person they spend the most time with during these critical years of development, so it is important to understand the foundation of cognitive development. 

We know that brains are built over time, and that experiences affect growth and development. Developmental psychologist Jean Piaget provides one theory of cognitive development which explains how a child develops an understanding of their world through their play and exploration. He describes development as a process that occurs due to interactions with the environment. According to Piaget, there are four stages of cognitive development, which are listed below. All children progress through the stages in the same order; however, the ages in which children progress through these stages may vary.

  1. Sensorimotor (birth to age 2)
  2. Preoperational (from age 2 to age 7)
  3. Concrete (from age 7 to age 11)
  4. Formal Operational (from age 11 through adulthood)

The infants and toddlers in your care will likely be working through the Sensorimotor Stage and may progress to the Preoperational Stage. During this time, infants and toddlers learn about their world by using their senses to interact and explore their environment. They touch, squeeze, poke, shake, bang, and mouth materials to explore. A child’s main achievement during this time is developing object permanence, which is the knowledge that a person or object still exists, even if it is unable to be seen. This requires a child to have the ability to form a mental representation of the object. Examples of this stage include:

  • An infant who cries when you leave the room: As children grow, they begin to understand that even if you are not next to them or able to be seen, you will return. Therefore, it is especially important to support young children during drop-off and pickup times with their families.
  • An infant who startles during a game of peekaboo: Prior to achieving object permanence, an infant believes when an adult’s face is covered, that they are no longer there. Therefore, the child may startle easily when you move your hands. 
  • An infant that kicks their legs to make the objects on an activity mat move or shakes a rattle to hear the sound that it produces.
  • A toddler that fills a bucket with small wooden blocks, dumps the wooden blocks onto the floor and fills the bucket again.

As children progress to the Preoperational Stage, they begin to think about things symbolically. This is what allows them to use a word or object as something other than itself. At this stage, children begin to remember and repeat actions or words used previously. During this time, children’s thinking is still egocentric, so they have difficulty seeing the viewpoint of others. Examples of this stage include:

  • Pretending a block is a cellphone and calling the doctor
  • Using a blanket as a superhero cape and flying around the room
  • A toddler who yells “mine” and takes the ball that another child is using because they were playing with it earlier in the day.

The Importance of the Early Years

While the brain can be influenced at any age, it is the most impressionable in the early years. The first three years of a child’s life are crucial for brain development because the experiences they have help to shape the architecture of their brains. New brain connections are being developed every second. These are called synapses. The more often a child has an experience (positive or negative) the stronger those synapses will become. Adults can support healthy brain development by including the following in their care of infants and toddlers:

  • Engage in tailored, back and forth interactions.
  • Share your thoughts, feelings, and needs aloud.
  • Support active, child-led learning.
  • Model persistence.
  • Provide responsive caregiving that builds self-regulatory skills.
  • Create flexible, individualized routines.

Cognitive development is strengthened when children are healthy, emotionally secure, and socially connected. It is your job to make sure:

  • They are healthy, by keeping a clean environment and promoting healthy habits.
  • They are emotionally secure, by responding to their cues and addressing their needs immediately in a nurturing manner.
  • They are socially connected, by fostering relationships between them and others during play and caregiving routines.
  • They can construct their own ideas of the world around them and investigate their ideas through open-ended, safe experiences. 

Early experiences are powerful. Children who accumulate negative experiences in their early years carry the effects with them throughout their lives. In other words, early experiences last a lifetime. Remember that while you are changing diapers, picking up toys, singing songs, cleaning up spilt milk, and performing all the other tasks you do on a daily basis, you are also influencing a developing brain.


The brain does amazing work during the first three years of life. Watch this video to learn more about how experiences influence the developing brain.

You Make a Difference

Watch this video to learn more about how experiences influence the developing brain during the first 3 years of life.


Infants and toddlers learn by watching, moving, tasting, smelling, touching, and doing. The experiences offered across areas of development contribute greatly to growth and learning. Infants and toddlers learn from your actions, how you speak to them, and the way you engage with them. Take time to review the strategies listed below, which highlight ways to support cognitive development for the infants and toddlers in your care:

  • Touch, cuddle, and sing to babies and toddlers.
  • Read to infants and toddlers. Let them explore the pages, illustrations, and textures. Talk about colors, sizes, shapes, and other features of the book.
  • Provide toys that make simple, pleasant noises such as rattles and shakers. Help infants discover the connection between their movements and the noises. Talk with toddlers about the different sounds an object makes—compare the sounds of different drums, bells, or shakers. 
  • Place shatterproof mirrors at infants’ and toddlers’ eye levels. Describe their movements as they explore their own images.
  • Engage the senses. Talk about the taste and smell of bottles or food. Offer easy-to-clean toys with a variety of textures that are safe for infants to put in their mouths. Consider mats or soft spaces with different fabrics.
  • Hold and rock infants and toddlers to communicate reassurance and comfort.
  • Play simple movement games like, Row Your Boat, Pat-a-Cake, and peekaboo.
  • Extend the sounds and words used by infants and toddlers; for example, if a toddler says, “Me home,” you might say, “You want to go home. After snack time, Daddy will be here to pick you up and go home.” 

Completing this Course

For more information on what to expect in this course, the Cognitive Development Competency Reflection, and a list of the accompanying Learn, Explore and Apply resources and activities offered throughout the lessons, visit the Infant & Toddler Cognitive Development Course Guide

Please note the References & Resources section at the end of each lesson outlines reference sources and resources to find additional information on the topics covered. As you complete lessons, you are not expected to review all the online references available. However, you are welcome to explore the resources further if you have interest, or at the request of your trainer, coach, or administrator.


How do you define cognitive development? What experiences have helped you develop as a learner? Use the Exploring Cognitive Development activity to reflect on cognitive development. Take a few minutes to read and respond to these questions. Then, share and discuss your responses with a trainer, coach, or administrator.


There are many resources available to help you understand the importance of early brain development. Use the Developing Brain Resources document to explore additional resources developed by Zero to Three and the Center on the Developing Child.

To best serve all children, it is important to know the foundational stages of cognitive development through which all children progress. Use the Stages of Cognitive Development guide to review Piaget’s four stages of cognitive development. Print the chart to use as a tool in your classroom.


Developmental domains:
Specific aspects of growth and change in human development. The major domains of development include social-emotional, physical, language and cognitive
Thinking only of oneself, without regard for the feelings or desires of others
Symbolic thought:
The ability to represent different objects or experiences using the things at hand


True or false? Cognitive development is influenced primarily by genes.
Which of the following is not a way that supports infants’ and toddlers’ cognitive development in a positive way?
Finish this statement: When a toddler sees a cat and makes a “meow” sound, this is…
Which of the following is not an example of symbolic thinking?
References & Resources

Chick, N. (2013). Metacognition: Thinking about one’s thinking. Nashville, TN: Vanderbilt University Center for Teaching. 

Dodge, D. T., Colker, L. & Heroman, C. (2002). The Creative Curriculum for Preschool. Washington, DC: Teaching Strategies, Inc.

Galinsky, E. (2010). Mind in the Making: The seven essential life skills every child needs. New York, NY: William Morrow Paperbacks an Imprint of Harper Collins Publishers.

Gestwicki, C. (2016). Developmentally Appropriate Practice: Curriculum and development in early education (6th ed.). Boston, MA: Cengage Learning, Inc.

Copple, C., & Bredekamp, S. (2009). Developmentally Appropriate Practice in Early Childhood Programs Serving Children from Birth through Age 8, (3rd ed.). Washington, DC: National Association for the Education of Young Children.

Gonzalez-Mena, J. & Widmeyer, D. (2011). Infants, Toddlers, and Caregivers: A curriculum of respectful, responsive, relationship-based care and education. Columbus, OH: McGraw Hill.

Mooney, C. (2013). Theories of Childhood: An introduction to Dewey, Montessori, Erikson, Piaget & Vygotsky (2nd ed.). St. Paul, MN: Redleaf Press. 

The Center for The Developing Child. (2021). Harvard University.