What Is Epigenetics?
Epigenetics is the study of changes in the expression of genes that do not result from alterations in the sequence of the genetic code. Each person's DNA lays a groundwork for the development of physical and psychological characteristics, but the activity of genes can be modified by various factors. Scientists who work in epigenetics explore the mechanisms that affect the activity of genes.
The chemical modifications that influence gene activity in this way are collectively called the epigenome. One major type of epigenetic mechanism, called DNA methylation, occurs when molecules called methyl groups attach to certain pieces of DNA, which can affect a gene's activity, turning its expression "on" or "off."
While these modifications occur naturally and help to steer development, the epigenome is also susceptible to influence by exposure to toxins and other environmental factors.
What Is the Importance of Epigenetics in Psychology?
All human characteristics, including psychological ones, are influenced to some extent by genetics. Since the epigenome modulates the effects of an individual's genome—and because it can be influenced by external factors—it is naturally a major area of exploration for those seeking to understand how individual differences, mental illness and other aspects of cognitive life take shape.
Behavioral geneticists and behavioral epigeneticists are scientists who investigate whether epigenetic changes can help account for vulnerability to certain forms of mental illness, including conditions such as depression and post-traumatic stress disorder. Another possibility that has received attention in recent years is the question of whether epigenetic changes resulting from traumatic experiences can be passed from one generation to the next, sometimes called intergenerational transmission of trauma. The molecular evidence for such transmission is very limited at present, though further research is required.