For some time, we have known that development results from the dynamic interplay of nature and nurture. From birth on, we grow and learn because our biology is programmed to do so and because our social and physical environment provides stimulation.
New research on early brain development provides a wonderful opportunity to examine how nature and nurture work together to shape human development. Through the use of sophisticated technology, scientists have discovered how early brain development and caregiver-child relationships interact to create a foundation for future growing and learning.
At birth, the human brain is still preparing for full operation. The brain’s neurons exist mostly apart from one another. The brain’s task for the first 3 years is to establish and reinforce connections with other neurons. These connections are formed when impulses are sent and received between neurons. Axons send messages and dendrites receive them. These connections form synapses. (Figure 1.)
Neurons mature when axons send mesages and dendrites receive them to form synapses.
As a child develops, the synapses become more complex, like a tree with more branches and limbs growing. During the first 3 years of life, the number of neurons stays the same and the number of synapses increases. After age 3, the creation of synapses slows until about age 10.
Between birth and age 3, the brain creates more synapses than it needs. The synapses that are used a lot become a permanent part of the brain. The synapses that are not used frequently are eliminated. This is where experience plays an important role in wiring a young child’s brain. Because we want children to succeed, we need to provide many positive social and learning opportunities so that the synapses associated with these experiences become permanent.
How the social and physical environments respond to infants and toddlers plays a big part in the creation of synapses. The child’s experiences are the stimulation that sparks the activity between axons and dendrites and creates synapses.
Infants and toddlers learn about themselves and their world during interactions with others. Brain connections that lead to later success grow out of nurturant, supportive and predictable care. This type of caregiving fosters child curiosity, creativity and self-confidence. Young children need safety, love, conversation and a stimulating environment to develop and keep important synapses in the brain.
Caring for infants and toddlers is mostly about building relationships and making the most of everyday routines and experiences. The Creative Curriculum for Infants and Toddlers (Dombro, Colker and Dodge, 1997) says that during the first 3 years of life, infants and toddlers look to caregivers for answers to these questions:
During the first 3 years of life, children experience the world in a more complete way than children of any other age. The brain takes in the external world through its system of sight, hearing, smell, touch and taste. This means that infant social, emotional, cognitive, physical and language development are stimulated during multisensory experiences. Infants and toddlers need the opportunity to participate in a world filled with stimulating sights, sounds and people.
Before children are able to talk, emotional expressions are the language of relationships. Research shows that infants’ positive and negative emotions, and caregivers’ sensitive responsiveness to them, can help early brain development. For example, shared positive emotion between a caregiver and an infant, such as laughter and smiling, engages brain activity in good ways and promotes feelings of security. Also, when interactions are accompanied by lots of emotion, they are more readily remembered and recalled.
Early development does not always proceed in a way that encourages child curiosity, creativity and self-confidence. For some children, early experiences are neither supportive nor predictable. The synapses that develop in the brain are created in response to chronic stress, or other types of abuse and neglect. And, when children are vulnerable to these risks, problematic early experiences can lead to poor outcomes.
For example, some children are born with the tendency to be irritable, impulsive and insensitive to emotions in others. When these child characteristics combine with adult caregiving that is withdrawn and neglectful, children’s brains can wire in ways that may result in unsympathetic child behavior. When these child characteristics combine with adult caregiving that is angry and abusive, children’s brains can wire in ways that result in violent and overly aggressive child behavior. If the home environment teaches children to expect danger instead of security, then poor outcomes may occur.
In these cases, how do nature and nurture contribute to early brain development? Research tells us that early exposure to violence and other forms of unpredictable stress can cause the brain to operate on a fast track. Such overactivity of the connections between axons and dendrites, combined with child vulnerability, can increase the risk of later problems with self-control. Some adults who are violent and overly aggressive experienced erratic and unresponsive care early in life.
Adult depression can also interfere with infant brain activity. When caregivers suffer from untreated depression, they may fail to respond sensitively to infant cries or smiles. Adult emotional unavailability is linked with poor infant emotional expression. Infants with depressed caregivers do not receive the type of cognitive and emotional stimulation that encourages positive early brain development.
When children have less-than-optimal experiences early in life, there is hope for the future. Understanding how brain development is affected by negative experiences gives us the opportunity to intervene and to prevent future difficulties. And, because we know about healthy early brain development and the experiences that infants and toddlers need, programs have been designed to help children develop the necessary skills that they may not have developed earlier.
In Missouri, the Parents as Teachers (PAT) program provides information about child development to parents whose children are between birth and age 5. The information is delivered by well-prepared parent educators during home visits and parenting classes, and through referrals to other agencies. An evaluation of the program showed that PAT children scored higher on measures of intellectual and language ability than children whose parents did not participate in PAT. PAT is available to all families in Missouri and is a good example of how caregiver education about child development can help children throughout their lives.
Early brain development research reinforces an important message about children: From birth on, children are ready and eager to learn and grow. Taking advantage of this situation means that all caregivers need to understand the importance of the early years and to recognize appropriate methods for stimulating children’s learning and growth. Providing educational opportunities to parents, grandparents, child care providers and other caregivers is a step in the right direction to guarantee productive early years. Sharing this message with policy makers is another strategy for ensuring that infants, toddlers, and young children and their caregivers receive the necessary education and support.
Here are some tips for how to effectively establish relationships with infants and toddlers and to promote early brain development:
Early brain development research reinforces the importance of caregiver sensitivity and responsiveness to infant behaviors and needs. What do insensitive and unresponsive caregiver-infant interactions look like? What do sensitive and responsive caregiver-infant interactions look like?
Below are some real-life examples of caregivers interacting with their 4-month-old babies. Although these are only brief examples of caregiver-infant interactions, consider what is happening to the baby’s development if most interactions are like these ones. As you read each example, put yourself in the baby’s position and “See the world through the eyes of the child.” Ask yourself: