Does DNA determine our destiny?
In a new book, DNA Is Not Destiny: The remarkable, completely misunderstood relationship between you and your genes, UBC Psychology Professor Steven Heine debunks the hype surrounding DNA testing and puts to rest our mistaken anxieties about our genes. He explores how our psychological biases make us fatalistic about genetics, and how these biases intersect with such hot-button topics as race, sexual orientation, crime, disease, eugenics, and genetic engineering.
At a recent book talk event Dr. Heine shared his research — and own genome sequencing results — to reveal the cognitive traps which make people overly fatalistic when they think about genes. He ranged broadly, discussing both historical and ethical concerns, and investigates how people’s beliefs about the power of genes influence their behaviour.
His conclusions about the promise, and limits, of genetic engineering and DNA testing upend conventional thinking and reveal a simple, profound truth: your genes create life — but they do not control it. We recently sat down with Dr. Heine to learn more about his research and what our DNA does — and doesn’t — reveal.
What can our DNA reveal about our nature, our origins, and our futures?
Our genes influence all aspects of our lives, although not usually in a straightforward way. Aside from a number of rare diseases in which a single gene can strongly predict a diagnosis, the vast majority of human traits and conditions are the product of many, many genes interacting together, and their expression is strongly shaped by experiences and various epigenetic factors. The problem is that people overgeneralize from their understanding of those rare cases of simple genetic determinism to the rest of human conditions in which genes are not at all deterministic. We grant genes far more power than they actually have.
How might people’s beliefs about the power of genes influence their behaviour?
People, the world over, are essentialist thinkers, which means that they have an intuition that the natural world emerges as it does as the result of hidden, internal, and powerful essences. And these intuitions about essences map so well on to people’s lay understanding of genetics that when most people are thinking about genes they’re NOT really thinking about genes; they’re thinking about essences. This means that people tend to think of genes as being ultimate causes, that will inevitably lead to a condition, that are natural (and thus good), and that carve up the social world into discrete and homogeneous groups. These are not only incorrect intuitions, they can sometimes have harmful consequences. For example, my students and I find that when people reflect on how genes are distributed differently around the world they become a little bit more racist. Likewise, when UBC students read about the existence of “obesity genes” they become more fatalistic about their weight and will eat more cookies. On the other hand, when people learn about the existence of “gay genes” they become more in support of gay rights. What I find interesting about all of this is that people don’t show these same kinds of reactions when they learn about the environmental influences on themselves. It’s just a much more difficult idea to understand that we are who we are because of our experiences. In social psychology, we refer to this difference as the “fundamental attribution error.” It’s because we view genes as being so powerful that people can get very anxious about the idea of genetic testing.
Why do we continue to buy into the belief that our genes control our destiny?
I think it’s both because we search for essences to explain the natural world and that we have a preference for simple explanations. This is reflected in the language that is used to talk about genes. President Trump attributes his success to having “a certain gene.” The media frequently summarizes genetics research as having discovered “the depression gene,” or “the infidelity gene.” This all contributes to the sense that an ultimate understanding of oneself can simply be found by having one’s genes sequenced. It is easy to imagine that we are who we are because of our genomes – that there’s a one-to-one correspondence between all of our traits and a matching set of genes. It was this simplistic imagining of genetic causes that undergirded the eugenics movement in the first half of the 20th century. Various governments, including that of BC, tried to improve society by sterilizing people with imagined defective genes.
What are the risks of DIY genetic testing with companies such as 23andMe and Ancestry DNA?
In doing research for my book I got myself genotyped by 3 separate companies. Interestingly, while they generally agree on the specific genetic variants that I have, they don’t agree at all about what conditions I’m at risk for, nor where my ancestors originated. My case isn’t an anomaly. One study found that different consumer genomics companies gave opposite predictions (i.e., increased risk vs. decreased risk) for the same genomes for one third of the conditions they covered. The problem is there is no consensus for how to estimate the risk for conditions that are predicted by multiple genes, as there is no consensus for what is the set of genes that predict particular conditions. But that doesn’t stop the companies from providing very precise disease risk estimates past the decimal point. The FDA has stepped in and has limited the kinds of disease predictions that consumer genomics companies can provide, although the regulations continue to be a moving target. Ancestry testing also has many inaccuracies, but it remains unregulated. Some interesting research by Wendy Roth at UBC Sociology finds that when people get surprising genetic ancestry results they sometimes make life-changing decisions, such as learning a new language, changing how they identify on a census, or joining new clubs. I think the key risk with these consumer genomics companies is that we have unrealistic expectations about what our genomes can tell us, so that when these companies overpromise on what they can deliver, we are susceptible to believing it.
Is there a way to become less fatalistic about genes?
My students and I have been working on this, and we’ve been finding that it’s surprisingly difficult to get people to respond in less deterministic ways to genetic ideas. For example, we find that people don’t seem to be very sensitive to the magnitude of a genetic prediction. They respond rather similarly to learning that a particular gene is a strong predictor from one that is a weak predictor – their take-home message often just seems to be “it’s genetic.” Our most promising finding is that the more genetics education people have received, the less fatalistic they are about genes. We believe that this is because people who have studied genetics learn about the vast complexity that governs the ways that genes lead to phenotypes. Perhaps if we can make people aware of just how complicated the network of genes, experiences, and epigenetic factors is, they will be less likely to view genes in such a fatalistic way.
Dr. Steven J. Heine is Distinguished University Scholar and Professor of Social and Cultural Psychology at the University of British Columbia. Heine’s pioneering research has challenged key psychological assumptions in self-esteem, meaning, and the ways that people understand genetic constructs. He is the author of many acclaimed journal articles and books in the fields of social and cultural psychology including Cultural Psychology, the top-selling textbook in the field. In 2016, he was elected as a Fellow of the Royal Society of Canada.
— UBC Psychology (@UBCPsych) April 24, 2017