The prospect of a future that we can predict but cannot affect is terrifying. Most of us don’t want to know the exact date on which we will die—or the exact cause of death—many years in advance. We like a bit of mystery, or the comfort of uncertainty. Like the Greek goddess Cassandra, cursed by Zeus with the power to see the future without the power to change it, we worry that knowing exactly how and when we will die, whether our romantic relationship will work out, or if our business will succeed or fail might cheapen the pursuit of our goals in the here and now.
And yet, as bad as some kinds of knowledge might make us feel, self-knowledge can be transformative. This is why the Oracle at Delphi exhorted visitors to “know thyself.” Self-knowledge is ultimately self-mastery.
Indeed, knowing our capabilities—both strengths and weaknesses—means figuring out what sort of people we are, and might yet be, and ultimately how we might pursue our lives.
Despite our worries, genes do not determine the day we’ll die or whether our relationships will succeed. Genes constrain, but they also enable, even enrich: A favorable genetic hand can help us learn how to play musical instruments, but it doesn’t make us expert pianists or dreadful drummers. And the better we know ourselves—the more we understand the genetic hand we’ve been dealt in the game of life—the more we can direct it to our advantage. Our genetic fortunes may yet be tamed.
Understand Our Ancestors, Ourselves
The most familiar kind of genetic self-knowledge is, well, about the family itself. Our ancestry is ultimately about our relationship to others and how those relationships inform on us. We want to know where we came from and why we are the way we are. Does our temper come from our Swedish side—the Vikings from whence our mother descended? Does our adventurous spirit hail from our Spanish side, which counts among its ranks explorers and romantic poets?
Apart from simple curiosity, maybe one reason so many of us want to understand our past is so that we can understand and—perhaps—alter our future. We want to know what kind of people our ancestors were so we can figure out what kind of person we are, the reasons we have to take pride in and celebrate, and what we might become. We look back so that we can understand the present and forge ahead to the future. We don’t want the past to own the present but to inform it.
Mortality, Or Who Wants to Live Forever?
Although many of us may not want to know exactly when we will die, we may want to know our disease risks so that we can anticipate symptoms and act to mitigate these risks. If we knew we might develop heart disease—whether our knowledge comes indirectly because of family history, or directly because of genetic testing—we would inform our doctor, and take certain medications to keep our heart ticking.
Similarly understanding what kind of physique we are likely to develop, how much fast-twitch or slow-twitch muscle mass we can build, may help us choose one sport over another.
Seen in this way, genetic knowledge is less of a curse and more of a blessing that enriches our lives. And so, Cassandra is the wrong metaphor. Prometheus is more fitting. We have fire within us, waiting to be harnessed. Even if we cannot master our fate, we may be able to improve our lives by treating our genome as a talisman, guiding our abilities and propensities.
Play to Your Strengths
The worst sort of advice is to do what you love. Our view is that you should do what you are.
Suppose you learn as a child that you find it difficult to control your impulses or that you’re likely to enjoy taking risks. While personality is to some extent malleable, twin studies show that our personality traits are moderately to highly heritable. Knowledge of the genetic roots of our personality traits might lead us to throw up our hands and curse the genetic lottery, or it might instead lead us to seek out activities or occupations that we’re likely to master.
Some people are better entrepreneurs than others, in part because they are especially adept at making good decisions under duress. Still other people may be fun to be around at parties because they are impulsive. While low self-control might make us spontaneous in some settings, having the sort of discipline that self-control enables is important when we make important choices. Knowing that we tend to be impulsive, in part because of our genetics, may lead us to devise strategies to seek out the advice of friends or family. Like Ulysses tying himself to the mast to avoid ruin, knowing that we will be tempted by distractions may lead us to devise strategies to stay the course.
Choose Optimism
Journalists and movie producers often focus on the downside of knowing our genetic predispositions—after all, they traffic in drama. But there are many reasons to think people would want to know the extent to which their disease risks and personality traits are governed by their genes—not so they can revel in sorrow, but to act with knowledge. Forewarned is forearmed. We can satisfy our curiosity about who we are and change our behavior to become better at the things we struggle with or expert in what we already excel. Knowing that you’re not especially musical may lead you away from ambitions in the symphony, but it might also lead you to challenge yourself and play that instrument just for fun. Knowing that you’re especially tolerant toward risk may lead you toward a high growth startups rather staid established companies.
It seems likely that our tendency to be optimistic or pessimistic in the face of knowledge about our genetic endowment is itself heritable. But a predisposition to be terrified or excited about what genetics might tell us about ourselves does not mean more knowledge will be necessarily paralyzing or liberating. Rather, it means different people will have different attitudes about unlocking some of the secrets about what makes us who we are. Like genetic diversity, the diversity of attitudes about what genetics can reveal about ourselves is part of life’s splendor. In the era of genomics, the Delphic Oracle’s injunction to know ourselves beckons with every passing year.