A Dance of Nature and Nurture

The Bible tells us a story where parents eat rotten fruit and their children’s teeth become spoiled. Though this ancient text might be interpreted as allegory, the emerging field of epigenetics suggests a more literal reading. That is, our parents’ experiences (as well as our grandparents’ and great-grandparents’ experiences, for that matter) have a profound impact on us. This leads us to the field of epigenetics.

The Greek root of epi is “on top of” while “genetics” refers to DNA. Together, epigenetics studies the way life experiences alter gene expression without altering DNA sequence itself. These changes occur “on top of” DNA, and they are heritable from parent to child.

Were you taught to think of environment versus genes as competing, oppositional forces? If so dear reader, you are not alone. The nature vs. nurture debate leaves many of us with the false notion that life experiences and genes are separate. This couldn’t be further from the truth! Rather than competing with one another, nature and nurture dance with one another. This dance is the focus of epigenetics, which studies how gene expression (nature) is directly impacted by one’s environment (nurture). Put simply, your life experiences (as well as those of your ancestors) play a key role in how your genes are realized into real-life characteristics. Epigenetics is a marvel that explains how two identical twins possessing identical DNA develop divergent life trajectories and health outcomes.

Indeed, we can’t change the DNA we receive – but this is only half the story. With time, our DNA accumulates chemical “tags” that impact its accessibility to be read and transcribed. This promotes or inhibits the creation of certain proteins, which ultimately orchestrates how much or how little each one of our genes is expressed.

Life circumstances not only impact an individual’s epigenome, but some epigenetic changes endure into future generations. Rachel Yehuda, a pioneer in the field of epigenetics, commented: “what happens to our parents, or perhaps even to our grandparents or previous generations, may help shape who we are on a fundamental molecular level that contributes to our behaviors, beliefs, strengths, and vulnerabilities" (US Department of Veteran Affairs, 2016).

From generation to generation, certain epigenetic marks endure from parent to child, with animal studies suggesting that epigenetic memories may endure for up to 14 generations (Dean, 2018). In this way, a fraction of parental experience is stored in children’s cellular memories in the form of chemical tags. While most epigenetic tags are erased during embryonic development, a minority of these marks survive the process and are passed down trans-generationally (Jiang, n.d.). Perhaps this explains why children of Holocaust survivors are more likely to develop posttraumatic stress disorder in response to a traumatic event (US Department of Veteran Affairs, 2016).

Though the notion that our ancestors in part live within us may sound outlandish, epigenetics brings a scientific basis to this claim. With this in mind, I invite you to broaden your lenses in viewing yourself. If you would like to journey inward, ask yourself: Where do I come from? What is my historical legacy? What do I carry with me? Understanding that we are interconnected with our ancestors’ histories allows us to glimpse into where we come from, and thus, become aware of where we would like to go.

Rather than lamenting what we have inherited from our forbearers, remember this: epigenetics changes arose out of a need to adapt to a given environment. In other words, stress-induced epigenetic changes may have surfaced to aid in survival. For example, researchers find that wider noses correlate with populations whose ancestors lived in warmer regions, as a wider nostril allows more humidity to enter the nose (Medical News Today, n.d.). Similarly, defense mechanisms such as dissociation or denial may have arisen to protect from immense pain that could overwhelm a person’s nervous system and ability to cope. Understanding that epigenetic signatures are reflective of the context that shaped them might move us to feel gratitude and compassion for our ancestors, as opposed to blaming them for the epigenetic inheritance we’ve received.

As the epigenome is affected by distress, so too it is influenced by positive events. In this way, epigenetic marks can be reversed through favorable environmental conditions. For example, studies have revealed that nourishing interventions might “potentially delay or reverse aging-related changes in the epigenome” with the epigenetic aging rate in meditators “significantly reduced proportionally to the number of years of meditation” (Yanget al., 2021). The bottom line is: our epigenome is malleable, and so are we. With intention and awareness, we may reclaim a measure of agency.

Though epigenetics arose through observing clinical problems in the children of Holocaust survivors, it is a subject with wide resonance. If we can understand that we exist in a social, historical, familial, and cultural context, we may begin to untie knots of cumulative, maladaptive transgenerational coping that no longer serves us.

While we cannot change our historical legacies, undo our childhoods, or alter the DNA sequence we inherited, the miracle of epigenetics grants us a measure of agency over how our DNA is read. Decision by decision, we actively participate in the tango of epigenetics - how we rest, relate to others, respond to stress, move our bodies, breathe, nourish our microbiomes, and more, may enrich both our well-being and physical health.

Let us revel in a bottom-line full of hope; namely, that like a river, human beings are forever unfolding. Each moment is a gift that enables us to rework our epigenome – for our sake and for the sake of our children. What I'm about to say is may sound like spiritual hooey, but reader, I believe that elevating our health honors those who came before us. In a sense, perhaps healing ourselves heals them, too. We are interconnected with our ancestors in a way that science might never be able to uncover, and it is my belief that when we reach our highest potential, we lift our ancestors’ spirits as well.

“To forget one’s ancestors is to be a brook without a source, a tree without roots.”

-Chinese proverb