The “nature versus nurture” debate has been raging for thousands of years. Are people the products of their DNA, or of their upbringing and environment? The writings of both Plato and Shakespeare discuss this question. As recently as the past century, some big thinkers still subscribed to the philosopher John Locke’s “blank slate” theory, which held that each individual is born “formless” and is shaped by their environment and upbringing. Even more recently, some genetic scientists argued in favor of biological determinism, or the view that everything about a person is predetermined by their DNA.
Today, experts recognize that nature and nurture—far from being independent or at odds—engage in a complex dance. While DNA has a lot to say, a person’s genes and environment interact throughout their life to produce any number of outcomes. And the science of epigenetics lies at the heart of this interaction.
“Epigenetics describes how the human genome can adapt to cope with environmental factors,” says Jian Feng, an assistant professor in the Department of Biological Sciences at Florida State University. Specifically, epigenetics is the study of things that change the way genes are expressed—that is, whether they’re turned on or off. Changing gene expression can fundamentally alter the activity of that gene without giving it a mutation.