My Beautiful Genome

by Lone Frank

  “The debate about nature versus nurture is over,” the American psychologist Eric Turkheimer has briskly declared. “The bottom line is that everything is hereditary, and this is a conclusion that has surprised all camps in the debate.”26

  The logical consequence of this outlook should be not to focus narrowly on our genes. Rather, we need to use our genetic knowledge as a springboard for a greater understanding of ourselves, about how we inherit a certain quality, whether a disease or a behavior, by subjecting our personal genetics and our physical selves to a specific environment. By choosing to follow a particular diet or take a particular form of exercise, you may prevent an unfortunate combination of variants in your genome from expressing itself in the form of heart disease or diabetes. In the future, by partaking in special relationships or special mental or social activities, you may be able to dampen the effect of a gene that cranks your nervous system into an undesirable gear.

  SO, HERE WE’VE finally reached that question of how much we’ll gain when we fully grasp our genetic ballast. Daniel Weinberger isn’t so sure it’s a good idea to delve too deeply into our many mutations and alterations, and seems worried we’ll get stuck on the idea that genes are fate. Of course, he’s right that we are far from a sure recipe for how we should respond to the news that we carry a particular gene variant.

  Yet, after my first taste of SNPs, my curiosity gets the better of my worrier reserve. I’ve filtered my raw data from deCODEme through the Promethease program and identified my COMT variants, but I want to know more. What about the other genes that we are beginning to realize have behavioral or psychological significance? Will I be able to understand myself and my idiosyncrasies and tendencies better if I look deeper?

  I’m at least going to make the attempt. At home in Copenhagen, I’ve promised to make myself available to a battery of researchers who are trying to show how genes and childhood experiences interact to form personality itself.

  6

  Personality is a four-letter word

  We continue to shape our personality all our life. If we knew ourselves perfectly, we should die.

  ALBERT CAMUS

  “WE’RE TESTING FOR twelve genes. So, we need to fill that many test tubes. And a couple extra as controls.”

  The young doctor plops a row of test tubes on the table and goes out to get an appropriate needle to stick into my arm. We know each other already from a previous occasion. She doesn’t have the perky ponytail this time, but she was the person who interrogated me about my immediate family members – and their relationship to alcohol and psychological illness – for a research project on personality, depression, and genes. Now, we’re reunited in a basement beneath Copenhagen University Hospital, to take care of the genetic side of things. There is a major renovation going on, so we’re huddled around a low coffee table that’s been incongruously placed in the hallway, amidst the chaos of construction.

  “You’ve got some really nice veins,” she says, acknowledging the slightly swollen blue vessels running down my left arm. They virtually offer themselves to the needle. Nevertheless, she somehow manages to work it so that only a tiny trickle of blood is lured into the needle. She tries to improve the flow by nudging the needle back and forth inside the vein. It doesn’t help – in fact, it hurts.

  “Let’s try the other arm,” she says, quickly puncturing my right arm. The result is the same. “Seven years of training,” I think to myself, “and what do they really learn in medical school?” I bite my tongue. In the end, I asked for this; I volunteered to be a guinea pig. The deal with the researchers at the Center for Integrated Molecular Brain Imaging is straightforward: they get a ream of completed questionnaires and copious amounts of blood from me, and I am allowed to discuss the results of my personal genetic tests with the center’s director, Gitte Moos Knudsen, in return. I was able to extract this special favor because she and I share a fascination: we’re “insanely interested in what creates individual differences in behavior and personality,” as she puts it.

  But what exactly is personality?

  Here, you have to leave the molecular behind and move into psychology, where personality research traditionally resides. As opposed to molecules and neurotransmitters, which are made of atoms and chemicals, personality appears to be odd and ethereal. We have a clear intuition of what it is, but it is hard to find a crisp, sharp formulation. You might describe one of your friends as helpful, patient, and a little introverted, or yourself as bright, generous, and sociable. But squeezing the phenomenon of personality into a definition is a little like shoveling sand with a sieve. What in the world are you measuring?

  And there is the burning question of where this indefinable quality comes from. Is personality readymade or is it created and shaped by life experience? If it is the latter, what shapes it – the actions of a parent, for good or for ill? The myriad random acts that accumulate in a lifetime?

  If you ask parents, you will typically hear them say that their child’s personality was apparent from birth. “Little Laura was hot-tempered from day one” or “Harry had the most serene temperament right from the start.” In other words, we think we know very quickly what sort of child we’re dealing with and, in a sense, that means we can just sit back and watch that personality unfold over the years. There is not much to be done about it one way or the other.

  Yet, ever since Freud described childhood as the key to all understanding, psychology has scoured early experiences and influences for answers to pretty much everything – just as we continue to do in our everyday lives. We happily refer to events, moods, and feelings from decades ago to try to explain our reactions in the here and now. We look for patterns in our thoughts and behaviors that derive from our childhood among our parents and peers. A bad relationship with a long-dead mother gets the blame for his introverted and sour personality in middle age. Growing up in the countryside with a huge horde of siblings is the reason she is vociferous and domineering at home and at work.

  But how reasonable is this?

  This was a subject I regularly debated with my father – though neither of us had anything but vague assumptions to support our arguments. In his later years, he developed a bad conscience about practices he considered, after the bulk of his childrearing was complete, to be parental sins. All his adult daughter’s problems, he believed, must have their roots in her upbringing. Was it, perhaps, his overwrought expectations that meant I had chronic issues with dissatisfaction and unfulfilled ambitions? I wasn’t so sure. My father retorted that unquestionably, it was too early for me to start learning the alphabet when I was still being toilet-trained as a two-year-old. Well, I couldn’t remember any of that. But in a faded snapshot, I’m sitting on the potty with lettered wooden blocks strewn before me spelling the word C-A-T. I don’t look unhappy. Sure, it may have been pushing things a bit to insist that I should be able to read before nursery school, or that our morning bike ride to the school was spent calling out chess moves, back and forth – playing “blindfold chess.”

  My mother thought this sort of thing was madness, bordering on child abuse. Yet, though there were quarrels over when I should be put to bed, during daylight hours I was my father’s daughter, his accomplice in my upbringing. It probably helped that reading was accompanied by rewards: every time a whole sentence of Dick and Jane was read aloud, I got a nice, plump raisin; when an entire page was complete, I’d get a piece of candy. And praise, of course. Since then, like the proverbial Pavlovian dog, I have associated reading with the ingestion of sugary substances. I practically salivate at the sight of a book.

  Still, I maintain that none of this harmed me. Not as such. I don’t go around with a feeling that anyone forced me to do anything I didn’t want to do. To my guilt-ridden father, I used to point out what happened when I finally toddled off to nursery school, Dick and Jane tucked under my arm: I discovered that my fellow three-year-olds couldn’t read as much as their own name. So I promptly renounced all my training. Neither
raisins nor caramels made any difference. In the end, it was far more important to be like the other children than to do what Daddy wanted.

  These days, in my adult incarnation, I gladly argue that, on the whole, childhood should not be burdened with culpability for whatever goes wrong in life. Or right, for that matter. As children, we are stuck with the parents we have and the upbringing they give us, and both can be a trial. But at some point, we take over the controls for ourselves. Thereafter, life is pretty much our own responsibility.

  My father wanted terribly to accept this, but he never bought it entirely, perhaps because he did not himself feel that he had broken free of his parents or his childhood, to which he traced much of his own personality, especially the more difficult aspects of it.

  Who is right? How does this work? What can you say about the source of your personality and its biological mechanisms?

  THESE ARE SOME of the central issues being plumbed in the field of personality research, which is experiencing a renaissance. In good part, that resurrection is driven by the fact that scientists have finally come up with a good model for personality and can use genetics to explore it. No longer are researchers stuck fighting over ideology-tinged theories, from classical Freudianism, to psychodynamics, to social psychology. With the genome available for investigation, personality research is joining the ranks of true science.

  The number of the beast is the five factor model. As the name implies, the model identifies five general personality traits, or personality dimensions: openness, conscientiousness, extroversion, agreeableness, and neuroticism. These ‘Big Five’ dimensions describe a range of behavioral tendencies in everyone’s character. Neuroticism is the tendency to lose yourself in negative impulses, while extroversion is the tendency to seek company and be confident. Openness is the tendency to engage in new and different views and experiences, while conscientiousness is the tendency to plan, be dutiful, and exercise restraint rather than spontaneity. Agreeableness speaks for itself.

  Each of the five dimensions is composed of six facets, which could better be described as specific traits statistically associated with the general dimension. Warmth, gregariousness, and excitement-seeking are facets of extroversion. Self-discipline and order belong to conscientiousness. Hostility, depression, and anxiety are tied to neuroticism.

  Despite the neat boxes and categories, this does not build up into a watertight, idiomatic definition of personality. Instead, many psychologists purport that we are dealing with a set of basic dispositions that outline a general pattern for how we think, feel, and act and how we react to the world around us. You can also put it more abstrusely. For example, Daniel Nettle, a psychologist at the University of Newcastle, in the UK, describes personality traits as “stable individual differences in the reactivity of mental mechanisms designed to respond to particular classes of situation.”

  You have to imagine that all humans are equipped with the same basic feelings and reactions. How easily these are engaged in each of us and how powerfully they unfold varies greatly. People with a neurotic personality react especially easily to the register of negative emotions, which they also experience very powerfully, while a personality characterized by extroversion experiences a much stronger response to positive emotions.

  Contrary to a multitude of other personality tests, the five factor model does not derive from a chromium-plated theory of personality; it is data-driven, a crystallization of measurements and observations from laboratory experiments and real life. Oddly enough, like behavioral genetics, it can trace its history back to good old Francis Galton. Darwin’s talented and enterprising cousin desperately wanted to measure human “character,” as he called it, and he had the excellent idea that features of our personality must necessarily appear in language: in the way we speak about each other. Therefore, Galton went to the dictionaries and collected somewhere in the range of a thousand English words that described facets and nuances of character or personality. By classifying synonyms, he boiled the heap down into far fewer unique personality traits, which in 1884, he published in an article entitled “The Measurement of Character.”

  The modern reinvention of personality research grew out of the same lexicographical method. In 1936, the British team of Gordon Allport and H.S. Odbert burrowed through contemporary English dictionaries and came up with a list of 4500 adjectives that they believed fully described all possible human personality traits.3 But things only got moving with measurements of actual people in the 1950s and 1960s, when researchers began to let subjects characterize themselves as well as others. To do so, subjects would often link a number score to the many descriptive words.

  With this breakthrough, some order could be glimpsed in the apparent cacophony of the psyche. It became clear that certain aspects of personality go together. Using factor analysis, a tool of mathematics that can determine how a huge quantity of data can be grouped together and made coherent, researchers could reduce the many ingredients down to an essential few.

  The first person to make use of this statistical method was Raymond Cattell, cofounder of the University of Illinois’ Institute for Personality and Ability Testing, who discovered evidence for sixteen different, independent factors in data from a personality test he had developed. That work laid a foundation for later investigations of personality data. Then, in 1961, Ernest Tupes and Raymond Cristal of the US Air Force Personnel Laboratory applied factor analysis to data from eight different major studies, revealing the five factors for the first time. Their identification of the factors was confirmed just two years later by a colleague, Warren Norman of the University of Michigan. Throughout the rest of the decade, the dominant idea among researchers was that personality traits could be distinguished and measured; that there was something tangible about a human being’s internal makeup which could be used to predict behavior.

  But then the tumultuous 1970s got in the way. A powerful ideological wind was blowing, and it shook personality research. Now, the social psychologists had their turn, and they believed an entity as reactionary as a “stable personality” did not exist. Leading figures in the field, such as the American psychologist Walter Mischel, argued that who we are is dependent on circumstance, and personality traits are behaviors and attitudes we adapt in given situations. Some went so far as to say that personality is nothing but a construct, something we invent about others and mentally impose on our view of them – to create at least an illusion that the world has permanence.

  After the social psychology revolt, the early pioneers of personality research – Allport and Odbert, Tupes and Cristal – were largely forgotten, but science reported once again to the field. This time, the prominent psychologist Lewis Goldberg, dictionary in hand and factor analysis in back pocket, blazed his way to the five dimensions of personality and coined the “Big Five” designation. During the 1980s, the model won broad acceptance among psychologists, and people finally had a common language with which they could discuss personality.

  A consensus emerged that you could describe an individual’s personality in a coordinate system involving five axes, one for each factor. You are not simply extroverted, agreeable, or neurotic – you contain some traits from every single dimension, but are more or less characterized by one or another. Your score placed within these five dimensions, so to speak, could be considered to be your overall psychological chart, akin to a series of your physical measurements. Chest, waist, hips, for example, or height, weight, and body fat.

  The American researchers Paul Costa Jr. and Robert McCrae distilled and decoded the five factor model in their whopper of a book, Personality in Adulthood. Published in 1990, it is still the closest thing there is to a Bible of personality. The duo also constructed a personality test that has gradually become the gold standard. The complete NEO Personality Inventory-Revised, or NEO-PI-R, introduced in 1992, consists of 240 questions – or, rather, statements – that are assessed on a scale from 1 to 5, in relation to how well they fit the subject. These ar
e simple, psychologically elegant, statements, such as:

  I have excellent ideas.

  I am not interested in abstractions.

  I am the life of the party.

  I don’t like to call attention to myself.

  I insult people.

  I am easily disturbed.

  I am always prepared.

  I have a soft heart.

  I change my mood a lot.

  I may not have the softest heart around (I’d give it a 3), or be the life of the party (though I never understood why my excellent jokes often seem to chase people away). But do I perhaps insult people? Well, no more than to demand a 4,I should think.

  THE FIVE FACTOR model has its detractors. Some are piqued by its very simplicity – they argue that just five dimensions are too rough a measure to say anything meaningful. Others question whether the five factors are truly independent; some research indicates they may not be. If they are not independent, the model might eventually be reduced to a four factor model or a three factor model, leaving personality psychologists with a very limited palette of “genuine” traits with which to explain the multiplicity of human personality.