The Interaction of Biology and Environment

Adapted from Transforming the Workforce Chapter 3

Key Takeaways

  • The capacity for learning is grounded in early brain development.

  • Human development is a continuous, dynamic interplay between biology and environment. There are critical periods where the developing brain is especially responsive to early experiences.

  • Early experiences affect how the brain develops. They also affect gene expression, which means that they affect a gene’s instructions for creating proteins or other products that lead to growth and development. Environmental factors may affect child development differently depending on underlying individual genetic characteristics.

  • Economic adversity may lead to more stress-related disruptions in the development of brain areas associated with important self-regulatory and cognitive functions, impairing the capacity to deal with other disadvantages or social difficulties children may experience.

  • Some children are more responsive to the social environment and are affected by both negative and positive environmental factors.

Chapter Summary

During early brain development, new neurons and synapses form and differentiate into specialized cells and brain regions that perform specific functions, laying the foundation for cognitive and social and emotional development. The developing brain is easily molded, making it highly responsive to experience and stimulation. Enriching environments will support healthy brain development, but exposure to stress and adverse childhood experiences (ACEs) can result in changes to the brain that can impact behavior and the capacity for learning. 

This video below, from the Center on the Developing Child at Harvard University, explains why:

Cognitive development is guided by continuous, bidirectional interactions between human biology and social environment. Both normative and maladaptive development are dependent upon the interaction of genes and environment. Gene-environment interplay consists of three interactive processes: gene-environment interaction (GxE), gene-environment correlation (rGE), and epigenetics. During critical periods of development, such as early childhood, the brain is especially responsive to the effects of physical and social environmental exposures. This is when exposures can result in irreversible changes in brain circuitry. Early learning experiences and environments influence long-term developmental and academic trajectories.

See this next video on "serve and return" interactions, also from the Center on the Developing Child at Harvard University

Psychosocial adversities during the prenatal period and early life have biological consequences. Examples of active stressors include chronic threat or danger, but a lack of nurturing and supportive relationships create significant stress as well, especially for young children. Early adversity (adverse childhood experiences) has lasting effects on brain development, stress response systems, coping mechanisms, and learning, and has been linked to problems in physical and mental health in adulthood. New studies also show that prenatal exposure to chronic stress also influences the developing brain because fetal development is affected by maternal stress.

The third of this series of videos from the Center on the Developing Child at Harvard University helps to explain how prolonged stress can reduce neural connections in the brain:

Children living in poverty may experience multiple stressors, such as lack of food and exposure to violence, making them more susceptible to disruptions in brain development, especially with cognitive and self-regulatory functions. These changes may manifest as academic and social problems when the children enter early childhood programs or school. However, children are not all equally sensitive to negative and positive environmental factors. Some are more responsive to social environment, showing more negative or positive outcomes depending on the environment in which they grow up. Highly susceptible children are not just affected by unsupportive conditions; they may also benefit disproportionately from positive environments. Understanding the interplay between environmental and genetic factors in relation to individual differences in brain development is important for designing early interventions.

Key Quote from Chapter

“Given the foundational and rapid processes of brain development during foundational periods of early development, this is a window of both great risk of vulnerability to developmental disruption and great potential for receptivity to positive developmental influences and interventions.” (pg. 60)

Questions for Policymakers, Higher Education, and the Workforce


  • Does your state provide resources or encourage research-based interventions or other types of support to help reduce prenatal exposure to stress?
  • How does your state provide these resources to help children and their parents through adverse situations? Where are these services provided?

Higher Education:

  • Do teacher preparation programs include coursework about the impacts of adversity on young children?
  • Do teacher preparation programs adequately teach the science of brain development to future educators, those who will work with young children as well as those teaching older children?

B–8 Workforce:

  • What information do you have about the backgrounds of young children in your care?
  • Do you have the opportunity to sit down with each family and discuss life stressors family members are facing as well as set goals for their children?