Why is early brain development so important?-

The human brain is like a house, built from the bottom up over time. Our brain architecture is comprised of billions of connections between individual neurons across different areas of the brain. Collectively, these connections enable lightning-fast communication among neurons that specialize in diverse brain functions.

Our youngest years are the most active period for establishing brain architecture, laying either a firm or a fragile foundation for all future growth. There’s a famous saying that “skills beget skills” —that is, all abilities are constructed on top of capacities developed earlier. This is true in the brain, where babies’ earliest brain connections serve as the bricks and mortar for new, more complex neural circuits. It’s also true in our behaviors, where early mastery of cognitive, social, and emotional competencies makes all later learning easier, more efficient, and more likely to continue.

What matters more - nature or nurture?+

It’s actually a false dichotomy! Think of it this way: our genes (“nature”) provide the blueprint, but our early environments and relationships (“nurture”) carry out the construction, determining how our brain architecture actually gets built.

Through a process known as epigenetics, our external experiences can literally switch our genes “on” and “off.” So, the genes a child inherits from her parents are expressed differently depending on the relationships and interactions she has as she develops.

For example, responsive caregivers who “serve and return” with a child help that child develop stronger brain connections. Like a game of Ping-Pong, when an infant or toddler gestures, babbles, or cries (“serves”), and an adult responds appropriately with eye contact, words, or a hug (“returns”), connections are strengthened in the child’s brain. The more consistently these interactions happen, the more frequently a child’s neural circuits for learning and memory are activated, making them increasingly strong over time.

This means that many human characteristics—from personality to cognitive ability—are not shaped by genes alone, as we once believed. Take intelligence: though we historically viewed IQ as genetically predetermined, we now have ample evidence to show that it is influenced by life experiences, most profoundly education.

What ages / years matter most? +

As a general rule of thumb, earlier is always better, especially before the age of five. During this period, our brains undergo their most rapid development, forming more than 1 million neural connections every second. Our brains have high plasticity, meaning they are their most open to adaptation and growth. This means that for better or for worse, our environments and relationships during our first five years have unparalleled impact on the neural circuitry we’ll rely on for the rest of our lives.

Within our first 1,000 days of life, there are shorter windows—known as “sensitive periods”— during which specific brain circuits develop. All circuits undergo a two-part process of proliferation, when large numbers of neural connections are formed, and pruning, when unnecessary linkages are clipped away to make the brain’s pathways more organized and efficient. Connections proliferate and prune in a prescribed order, with later, more complex brain circuits built upon earlier, simpler circuits. As this graph from the Center on the Developing Child shows, our basic sensory pathways for vision and hearing grow dramatically in our initial months out of the womb, followed by our early language skills and higher cognitive functions. While the timing of sensitive periods is genetic, children’s experiences within them determine whether the circuits formed are strong or weak. These periods are windows of opportunity for robust brain development, rather than windows of inevitability. If children don’t receive adequate visual, verbal, and cognitive stimulation—i.e., healthy amounts of talking, singing, reading, and nurturing—in these critical first years, their neurons will not connect to one another properly, laying a shaky foundation.

So, is it a lost cause in later life?+

No! The brain’s capacity to form new neural connections, learn, and adapt continues throughout our life. But, as the graph below illustrates, that ability decreases dramatically with age, because the amount of effort required to change the brain increases. It’s easier—not to mention more cost-effective—to influence a child’s brain architecture in the first five years than to rewire its circuitry in adulthood. As a basic principle, earlier is better than later.

So, what skills help kids succeed? +

The science of learning shows that language, math, social and emotional competencies are inextricably intertwined both in our brains—where their neural circuits are cross-wired—and in our behaviors and outcomes. In fact, our cognitive and social-emotional skills sprout from the same roots: a foundational set of skills called executive function and self-regulation, which develop in early childhood and enable us to plan, focus attention, remember instructions, and juggle multiple tasks successfully.

This interrelationship continues throughout all development and learning. Imagine two kindergarteners working on an arithmetic problem. In addition to understanding addition and subtraction, their motivation, cooperation, and ability to resist the impulse to run out to recess are critical to finding the correct solution.

So it turns out that “soft” skills are quite the opposite—they’re essential to achievement, acting as a booster rocket for everything we measure, including test scores. A recent meta-analysis of more than 200 social-emotional learning (SEL) interventions found that they significantly enhanced not only students’ behaviors and feelings about school, but also their academic performance. This new understanding of children’s integrated cognitive, social, and emotional learning is fueling a movement towards more holistic, Whole Child education approaches.

I’ve heard a lot about stress and adversity recently. Why do they matter so much? +

For decades, we’ve understood the threat that tangible traumas like lead paint, sexual predators, and viral diseases pose to children’s development and wellbeing. But only more recently have we begun to recognize the devastating consequences of less visible stressors like neglect, parental mental illness, chronic poverty, and other Adverse Childhood Experiences (ACEs). When children experience repeated adversities in the absence of caring adults, the effects literally “get under the skin.” How does this happen? California’s Surgeon General, Dr. Nadine Burke Harris, describes it below. This process is called toxic stress, and it explains why early childhood adversity has long-lasting effects on development. When young children’s brains and bodies are flooded with stress hormones, it can negatively rewire their neural circuitry, their hormone, cardiovascular, and immune systems, and even their DNA. The greater the severity and quantity of ACEs a child faces, the higher his or her risk for a host of physical health, mental health, and learning-related challenges in later life.