You reach that age where you start to notice signs of your parents in your appearance and behavior. The way the lines deepen around you eyes, the way you sneeze or answer a phone. You look in the bathroom mirror in the morning and you remember those times as a boy when aunties would size you up, inspect your features and draw comparisons to uncles and grandparents you’d never even met.
It didn’t mean anything back then. All a boy knows is his own individuality, the sheer thrill of free will. But today it feels terminal – as though you’ve been walking a prescribed path all these years and your boyhood sense of free agency was an illusion all along. When you’ve grown up around the Hindu notion of fate, seldom a comforting concept, those crow’s feet start to look like the etchings on a headstone. Saul Bellow has a lovely line in Herzog about “the time of life when the later action of heredity begins [and] the blemishes of ancestors appear…. Death, the artist, very slow, putting in his first touches.”
But then I think of Tim Spector, a professor at Kings College London, who does these experiments with twins – the identical kind, the true genetic clones. I got chatting to him when I did my twin story for Marie Claire, and what he told me suggests that “the later action of heredity” needn’t be so morbid after all. Our genetics may not be so prescriptive. Because Spector has discovered that however much is written in at birth – crows feet or otherwise – we still remain, in a scientific sense, free.
“I started looking at the question of why identical twins die at different ages, and of different diseases,” he says. “And it’s because our genes are not our destiny. In fact, those genes are shaped to some extent by our lifestyle, environment and individual experiences.”
His field is known as epigenetics and it’s one of the most dynamic areas of gene science right now. Better that he explains it himself: “It’s about how we switch genes on and off with chemical switches, without changing their structure. So you take identical twins, where one has diabetes and the other’s normal, or one’s happy and one’s depressed – and you look for these little differences in the chemical switches. That can tell you a lot about the disease and what might be causing it.”
In other words, epigenetics is revealing the limits of genetic data, as well as its possibilities. And that alone, is somewhat revolutionary. It wasn’t long ago that genes were hailed as the ultimate blueprint, full of actionable data about our lives, our health, our futures. Genes, we were told, would determine not only our physicality – both the way we age in bathroom mirrors as well as our propensity for cancer – but also our psychology, our beliefs, our religion even. It felt very Hindu, very deterministic and faintly hopeless. And Spector was fully on board – he was part of that wave of excitement that propelled the Genome Project to such prominence and launched companies like 23andMe, to which customers are sending cheek swabs by the million.
But Spector’s perspective changed, much as he has now shown that our genes can change. The title of his book spells it out: Identically Different: Why You Can Change Your Genes. Now he focuses on how we can alter our genetic make-up during our lives and pass on a different variation to our kids; how we can in a material sense overcome the past, and chart a new course. Nature, it turns out, can be nurtured.
One example from this year, reported in The Verge, showed that children who were born to women who’d had gastric bypass surgery prior to their birth, were genetically less prone to obesity. It was the surgery that tweaked the mother’s DNA and that was in turn passed down to the children.
Another example of how events in our lives can alter our genetic make-up: Rats which were conditioned to fear a certain smell passed on that fear to their kids. Did the fear of the parent rats manifest in their DNA? It’s not clear. But if psychological traumas or even chronic conditions like depression can appear as epigenetic markers – the chemical switches that Spector was talking about – then what about the effects of the pharmaceuticals we use to treat them? How is Prozac tweaking our genes exactly?
Perhaps, this field will lead to grand cures in time, perhaps identical twins will the key to humanity’s future. But at the very least, epigenetics cements the idea that we can change, not just in deed or word, but in our very nature, at the source code level. We are mutable creatures, and that sense of free agency as a boy, that wasn’t an illusion at all. The thrill of free will is real.
Some more Saul Bellow. In Seize the Day, he writes, from the perspective of Tommy Wilhelm, a failed actor, whose weakness and impulsiveness have led to an anxious and frittered life: “… In middle age you no longer thought such thoughts about free choice. Then it came over you that from one grandfather you had inherited such and such a head of hair…; from another, broad thick shoulders; an oddity of speech from one uncle, and small teeth from another.”
He’s like me in the mirror. And yet Tommy Wilhelm is a portrait of sadness, a man who feels trapped and burdened by life and the choices he’s made. And you want to grab him and say, Tommy, if only you knew, you’re free in ways you don’t even realize.