Home/Issue Areas/Early Development

Early Development

The first three years set the stage for lifelong success.

During the earliest months and years of life, the architecture of the brain is being built at an unparalleled rate in response to nurturing early experiences. Caring adults have a wonderful opportunity to foster feelings of trust and safety in babies, which helps toddlers establish a sense of self and become confident explorers.

Research shows that, to ensure a good start in life, all infants and toddlers need good health, strong families and positive early learning experiences.

Jump To:
    Children's early development is greatly affected by the mental health of the adults who care for them.

    Why It Matters

    Optimal child development, including during the perinatal period, is based on feeling safe, secure and loved.

    Primary caregivers should have the capacities to be attuned, consistently meet their child’s needs, and nurture healthy attachment, though these relationships are often dependent on the caregiver’s own mental health and well-being. 

    Healthy development isn’t always a clear path for infants and toddlers. Early identification and intervention for children with developmental delays or disabilities can improve cognitive and social skills, lead to higher achievement and greater independence and promote family competence and well-being.

    By the Numbers

    Earlier identification and intervention is more effective and less costly.


    Approximately 16% to 18% of children have disabilities or developmental delays.


    Infants and toddlers who have been maltreated are six times more likely than the general population to have a developmental delay.

    1 in 3

    1 in 3 infants and toddlers who received early intervention services did not later present with a disability or require special education in preschool.

    Source: ZERO TO THREE (2010, February 8). Making hope a reality: Early Intervention for infants and toddlers with disabilities.

    Science tells us that early experiences really do matter, and the connections that we have with the caregivers in our lives make a real difference in how we see and understand the world. ZERO TO THREE occupies a unique position in the early childhood landscape. We focus on a relatively small age range, but our reach is broad—from family, to policies, to all the service settings that touch the lives of infants. In terms of giving voice to the needs of babies, we don’t leave any stone unturned. 

    Brenda Jones Harden, PhD

    Policymakers must understand the critical early years.

    Our Impact

    We use evidence-based frameworks to develop early development resources for parents, professionals and policymakers.

    Through regular professional development opportunities and our ZERO TO THREE Journal, we provide early childhood professionals the latest research on the science of early development. Our team of experts works to raise awareness among parents and providers for early intervention services, as well as advocate for the expansion of those services to meet all children in need.

    We host an expansive library of early development resources, including our latest Podcast, The Earliest, which focuses on the role that caregiver and infant mental health play in early development.

    Early Development in the Classroom

    Related Resources

    Craving the latest news in early childhood development?

    Check out our Journal library, with the option to earn continuing education credits (CEUs) just for reading. Or, become a ZERO TO THREE Member to get free access to all Journal articles.