Early experiences can determine how genes are turned on and off or whether some are even expressed at all. This means that early childhood experiences and environments in which they grow, can help shape their brain architecture. This can have a big impact on how children develop and what they will be like as they age.
The epigenome controls which parts of the genome will function or not function. This can vary over time depending on whether positive experiences or negative influences are there to leave a chemical trace on the genes. These traces have the ability to be permanent or temporary which then affects how genes are switched on and off.
This is very evident in twins, as they have the same structural genome, but can have different experiences leading to a different epigenome. This difference in the epigenome can be manifested in different skills, health, behaviors and achievements in life.
Evidence has shown that chemical modifications driven by experiences can play large roles in the development of the brain and behavior. Research in both animals in humans has also shown that epigenetic changes that happen to the fetus during pregnancy can also be passed on to later generations. This can have an impact on descendants and their health. In contrast, healthy and supportive environments with positive experiences can have positive epigenetic effects which can enhance genetic potential.
Although new experiences can change our epigenome as we get older. Chemical traces left on our genes during early stages like fetal/infant development have large impacts on the brain and can potentially last for a lifetime. This shows at the molecular level how early experiences can have lifelong effects. This provides an important link between our external environment and the molecular basis that shapes our development and traits.