We know that the epigenome is far less stable than the genome. Adversity in childhood can leave epigenetic ‘scars’; diet and cross-fostering can reverse certain epigenetic effects; reversals can even be mediated through drug-treatment in adulthood. And yet epigenetic marks can also be stable enough to remain in adulthood and even pass through generations. It’s tempting to wonder whether resetting the epigenome might reverse the influence of abusive or neglectful parenting. Are rehabilitation strategies such as psychotherapy or fostering actually succeeding through molecular changes?

The genome, stable and unswappable, seals our fate. We may therefore be justified in exclaiming, “I was born this way!” Although, in light of our dynamically responsive epigenome, the way we respond to the things life throws is not wholly hard-wired. So perhaps we can leave some room for optimism and the possibility of diverting our genetic fate.