By Abha Ranjan Khanna
What is epigenetics and how does it relate to child development? Epigenetics is an emerging area of scientific research that shows how environmental influences – children’s experiences – actually affect the expression of their genes. Epigenetics explains how early experiences can have lifelong impact.
During development, the DNA that makes up our genes accumulates chemical marks that determine how much or little of the genes is expressed. This collection of chemical marks is known as the “epigenome”. The different experiences children have rearrange those chemical marks. This explains why genetically identical twins can exhibit different behaviours, skills, health, and achievement.
The brain is particularly responsive to experiences and environments during early development. External experiences spark signals between neurons, which respond by producing proteins. These gene regulatory proteins head to the nucleus of the neural cell, where they either attract or repel enzymes that can attach them to the genes. Positive experiences, such as exposure to rich learning opportunities, and negative influences, such as malnutrition or environmental toxins, can change the chemistry that encodes genes in brain cells – a change that can be temporary or permanent. This process is called epigenetic modification.
This means the old idea that genes are “set in stone” has been disproven. Nature Vs Nurture is no longer a debate – it is almost always both! Research shows that early experiences can determine how genes are turned on and off – and even whether some are expressed at all.
Physiological activity created by experience is powerful in shaping brain architecture and actually changes the chemistry that encodes the genes in brain cells. Put simply, the brain adapts to the experiences it has. Certain types of adaptations result in healthy systems, such as effective learning and memory, and other adaptations lead to the development of unhealthy systems, such as setting a stress response activation level that is too high.
The healthy development of all organs, including the brain, depends on how much and when certain genes are activated to do certain tasks. The experiences that children have early in life, therefore, play a crucial role in the development of brain architecture. Ensuring that children have appropriate, growth-promoting early experiences is an investment in their ability to become healthy, productive members of society.
The genes children inherit from their biological parents provide information that guide their development. For example how tall they could eventually become or the kind of temperament they could have. When experiences during development rearrange the epigenetic marks that govern gene expression, they can change whether and how genes release the information they carry.
Thus the epigenome can be affected by positive experiences such as supportive relationships and opportunities for learning …or negative experiences such as environmental toxins or stressful life circumstances.
Experiences very early in life, when the brain is developing most rapidly influence whether, when and how genes release their instructions for building future capacity for health, skills and resilience. That is why it is crucial to provide supporting and nurturing experiences for young children in the earliest years.
(Adapted from: Harvard Centre on the Developing Child – Resources)
(The writer is an occupational therapist)