What Galton Wrought Part 1: Men of Genius

Nature-Nurture-Noise (8)

A Brief Note

I have avoided addressing the Nature-Nurture debate because I find it so annoying. But before I proceed further in this series, I need to confront it. I find a historical perspective helpful in this regard.

The Man Who Measured Everything

It is June 1832 in Damaraland, a region of southwest Africa (present day Namibia). A young Englishman of excellent pedigree, and a budding scientist, is keenly observing a “Hottentot” (Khoekhoe) woman with unconcealed admiration. He is particularly struck by her huge, by English standards, buttocks, which he desperately wants to measure. He is thwarted, however, by a language barrier, and the only translator available is a missionary, whom, he suspects, will not be particularly keen to convey the request. But he is only temporarily stymied. An extremely resourceful man, he pulls out his sextant, by means of which he takes a series of measurements, from a distance, at every conceivable angle, and “registers them carefully upon an outline drawing for fear of making a mistake”. Then, with a measuring tape, he measures the distance from where he stood to his subject; whether she is still standing there or not is unclear. He repeats the measurement from a slightly different angle. He then employs trigonometry to calculate the precise dimensions of the object of his interest. He is immensely pleased with himself.

To this point, our English gentleman has led a rather desultory life. Though educated at the best schools he was a mediocre student and was admitted to Cambridge only because of his family’s prestige. Nor did he distinguish himself at Cambridge, where he failed to graduate. After he left Cambridge, he spent a couple of years hunting at the family estates of his friends but eventually tired of the hunting life. He probably got bored, because, notwithstanding his lack of distinction as a student, he has an extraordinarily active and inquisitive mind. What better way to engage that promiscuous curiosity than by travel, in particular, travel to exotic, previously unexplored regions. He was born at the right time for this, in the right country, and in the right social class. Britain’s empire is nearing its zenith, but much remains to be explored. Many of the more ambitious scions of wealth of his generation have set out for the hinterlands to make a name for themselves in the form of honors from the Royal Geographic Society. Francis Galton, for that is the name of the young English gentleman, sets his sights on southern Africa.

The trip was not really a success. Galton failed to achieve his major goals: to explore the region beyond Lake Ngami, recently discovered by Livingstone, a potentially valuable addition to the empire. Nor did he reach the Cunene River to the north as planned. But his copious notes, especially those on geography and ethnology—the latter including his measurements of the Hottentot woman--impressed the members of the Royal Geographic Society enough to grant him membership and ultimately its leadership. His subsequent account of his trip, Tropical South Africa, was a popular success.

Still prone to jumping from one intellectual preoccupation to another, he focused sufficiently to become a versatile scientist. Galton first turned from ethnography to meteorology to which he made significant contributions, not least the graphic representation of air pressure you find in today’s newspapers. Galton also coined the term “anticyclone’ for the winds that spiral outward from areas of high pressure. Though he never really abandoned meteorology he became increasingly preoccupied with psychology and anthropology, where his passion for measurement was allowed unbridled expression. First, he measured bits of anatomy, like height, finger length, the height of knees, head length and breadth, but his project also extended to more exotic bits of anatomy such as that of the Khoekhoe woman, culminating in his celebrated work on fingerprints, which became the foundation for forensic science.

Galton’s passion for measurement was not confined to anatomy. He also measured what he called “human faculties”, including personality traits and intellectual aptitudes.  He even devised a way to measure blushing. But Galton was not content to merely generate a bunch of numbers; he sought a way to identify the relationship between these numbers. In doing so he made important contributions to the fledgling science of statistics, perhaps most significantly the correlation coefficient, by means of which he searched for patterns in his mass of data. But much as he loved numbers and devising ways to “crunch” them, most of Galton’s statistical research was directed toward a larger aim, the study of biological inheritance, particularly as it applied to humans, and particularly as it applied to human faculties.

It cannot be said that Galton entered his study of inheritance of human faculties with the same dispassionate attitude he adopted toward the Khoekhoe woman’s buttocks. He clearly had an agenda, which he laid out on page 1 of his book Hereditary Genius. “I propose to show in this book that a man’s natural abilities are derived by inheritance, under exactly the same limitations as are the form and physical features of the whole organic world”. While few of his socioeconomic peers doubted the biological inheritance of human faculties, most particularly those that accounted for their socioeconomic success, his linking it to processes in “the whole organic world” was somewhat novel and bold. In truth though, as Galton saw it, he was just extending the insights of his more famous cousin, Charles Darwin, about the effects of natural selection on natural variation. Galton also employed Darwin’s analogy of artificial selection to make a much more controversial claim: “consequently, as it is easy, notwithstanding these limitations, to obtain by careful selection a permanent breed of dogs or horses gifted with peculiar powers of running, or of doing anything else, so it would be practicable to produce a highly gifted race of men by judicious marriages during several consecutive generations”. Galton wrote these words with some urgency, as he believed that the “British race”, the most valuable jewel in evolution’s crown, was in the process of genetic disintegration, because the lower social orders were producing babies at a rate far exceeding that of people like him. The term Galton coined for rectifying that problem is “eugenics”.

Zola: A French Version of Genetic Determinism

When Galton set out to champion his eugenics program, there was no science of genetics or even heredity. What passed for a science of heredity, for humans and racehorses alike, were vague notions of bloodlines. (Bloodlines were the primary rationale for the Aristocracy and the “divine right” of kings) The consensus was that there was something in the blood that we inherit from our parents and more distant relatives that explained who we are, not just our physical selves but our character as well. The environment in which you grew up played some role to be sure; it could mask or enhance the expression of your blood essence but not fundamentally alter it. Emile Zola provided perhaps the most eloquent and entertaining expression of this idea in his cycle of 20 novels, known as the Rougon Macquart. In this epic cycle, Zola set out to tell the story of Second Empire France under Napoleon III, by means of a social and “natural” history of five generation of a single family, the Rougon-Macquarts, for whom he created an elaborate genealogy.

At some point in the cycle, Zola began to confuse his fiction with science. The leading figure in a literary movement, known as naturalism, he relied on copious research on each segment of Second Empire society about which he wrote. Under the influence of the physician, Claude Bernard, Zola came to consider this research a form of science. He also believed that by making the art of the novel more scientific he could elevate it in the eyes of his peers. It is difficult to know how much of contemporary science Zola was aware of. He had certainly read Darwin.  There is no evidence that Zola ever read Galton, who was roughly contemporary, but he certainly would have found in him further justification for his “science-based” literary approach to explaining human character.

Zola’s idee fixe, his central preoccupation, was a nineteenth century version of genetic determinism. The first novel in the series, La Fortune des Rougon, sets the stage for the rest. It begins in a fictional provincial town in southern France, much like the one Zola himself grew up in. The protagonist, the woman from which the characters in all the subsequent novels derive is Adelaide Fourque, who is usually referred to as Tante Dide. (Tante is French for aunt; dide is polysemous: e.g. idea, plan, scheme.) Tante Dide marries a man named Rougon, whose background is thinly described, but he obviously derives from respectable stock, bloodwise.

Tante Dide, though, also has a lover named Marquart, a smuggler and altogether disreputable. She gives birth to a son, Pierre, by way of Rougon. The rogue Marquart fathers two children, Ursule and Antoine.

Those offspring that derive from Pierre (the Rougons) are successful, well-educated  and generally upper class, such as Pascal, a doctor and the main protagonist in Le Docteur Pascal. The Marquart line, on the other hand are poor: for example, peasant farmers (La Terre), coal miners (Germinal) and urban poor (L’Assomoir and La Ventre de Paris). (These four novels are by the most compelling of the fifteen in the cycle that I have read.)

There is a third branch, the Mourets, named after the respectable husband of Tante Dide’s daughter, Ursule Marquart. Mouret blood has the effect of lifting the Marquart line—which would have otherwise been destined to poverty—to the middle class.

Not only does Tante Dide’s choice of mate determine the socioeconomic condition of her offspring, grand-offspring and great-grand-offspring. Her own character taints them all. For she suffers from an emotional disability—only vaguely described—that devolves into dementia. This emotional defect is reflected in different ways in the Rougons, Marquets and Mourets. For the Rougon’s it is manifest through greed and avarice (La Curee, L’Argent). For the Marquart line Tante Dide’s emotional defect is more diversely expressed when combined with Marquart blood: alcoholism in L’Assommoir, prostitution in Nana, murder in La Bete Humaine, and pathological stubbornness in La Terre.

Fortunately, Zola’s scientific pretensions did not diminish his art much. (Except that his characters are unsurprisingly over-determined. Don’t expect a Zola character to “evolve”.)  Unfortunately, his “science” did reach a wide popular audience, who were, in any case predisposed to accept it. This was, by and large, the same audience that Galton addressed.  Though Galton would never have mistaken Zola’s novels for science, his own research was informed by the same simplistic dichotomy and the same deterministically hereditarian bias as Zola’s fiction. Nor was Galton, notwithstanding his passion for measurement, any more dispassionate in his exploration of human character than Zola.

What’s In the Blood?

Galton, though, did recognize that a science of heredity required more than a novelistic foundation. He set out to put the science of bloodlines on firmer scientific ground, putting to good use his passion for measurements. He didn’t attempt to identify the heritable factors in the blood; that would have been impossible, given the state of knowledge and technology at that time. Instead, he approached the problem indirectly, which is where his statistics of correlation came to serve such a prominent role. With these statistics, Galton was able to demonstrate a law-like relationship in the similarities between relatives, and by extension, the blood contribution of any relative to any individual. For instance, he determined that each parent contributes ½ of the heritable elements in the blood to their offspring, and each grandparent contributes ¼ to their grandchildren etc.

Perhaps even more important was Galton’s demonstration that what’s inherited is not in the blood at all. This result, in stark contrast to most of his research on heredity, came as something of an unwelcome shock to Galton, who had set out to prove Darwin’s view of inheritance, called “pangenesis”, according to which, the hereditary factors, called gemmules, circulated in the blood.

Galton tested pangenesis through blood transfusions between two varieties of rabbits. Given pangenesis, these transfusions should have caused the rabbits of one strain to exhibit characteristics of the other.  But though he diligently searched for any such change, Galton could find none. From this, Galton reluctantly concluded that there were no gemmules circulating in the blood, ergo no pangenesis. Through these experiments, Galton was widely credited for discrediting the theory of pangenesis. Galton proposed as an alternative that the heritable stuff is contained in some special reproductive tissue, which he referred to as “germ plasm”, a giant leap forward in the understanding of heredity.

Though Galton disproved pangenesis, he did not abandon the idea of blending inheritance, the idea that a red parent and a white parent will have pink offspring. The elements of the germ plasm were so tiny and numerous that they could be treated like grains of sand for the purpose of studying heredity. Galton was not unaware that some parental traits don’t appear in any of the offspring, only to appear again in the grand children, which would seem difficult to explain if the heritable stuff really blended. But as with the blending in pangenesis, there are ways around the problem. Galton’s solution to the problem had four elements. First, that the body consists of an enormous number of tiny, quasi-independent elements, each of which has a separate germinal substrate. Second, that there are a much greater number of germs than body units, so each body unit or character has a large number of associated germs. Third, that relatively few of these germs are active in development, the rest are latent. Fourth, that the latent germs “retain their vitality” and can still contribute to the development of its associated body part in future generations. These four theses, which seem to save the idea of blended inheritance, also comprise Galton’s theory of heredity, which came to be known as “biometry”.

But Galton was not content with a theory of heredity; he also wanted to explain how the tiny germs created the body parts and their integration, what we call “development”. He viewed development as the mutual attraction or repulsion of these tiny germs. As theories of development go, this one is pretty sketchy and does nothing to enhance Galton’s scientific reputation. But his simplistic formulation did serve as the template that helped shape many subsequent wrong-headed explanations of development as an extension of the principles of biological heredity.

First Version

Galton was well-aware that more than the interaction of germ bits was required to explain the details of the development of biometric traits like height, much less, psychometric traits like industriousness and intelligence, but he was also convinced that the other stuff wasn’t of much consequence. By way of demonstration, he proposed to measure the contribution of the germ bits, which he collectively labeled “nature” and the other stuff, to which he affixed the label “nurture”. Aside from its alliterative appeal, the nature/nurture framework has little to recommend it.  Let’s start with the second term.

What, exactly, did Galton mean by “nurture”? Initially at least, Galton seemed to view something like parental care as the only rival explanation for his psychometric traits like intelligence. In fact, intelligence is the trait (or pseudo-trait) that most influenced the subsequent nature/nurture debate. When Galton proved, to his satisfaction, that nurture of this sort was insufficient to explain the success of successful men in his “Men of Hereditary Genius”, he felt justified in attributing their success to their nature. But as Galton himself eventually came to realize, nurture of this sort is not the only alternative to nature. Accidents, illness, and other contingent events have dramatic impacts on what we achieve, but these factors can only be forced, with great effort, into the nurture category. What is “nurturing” about an illness or winning the lottery.

Galton’s conception of nature is also problematic. Originally, Galton conceived of nature as what we exit the womb with. But the paradigmatic exemplar of nurture occurs during gestation, within the womb. All sorts of potentially life altering events occur there. We don’t exit the womb in an unadulterated state of nature, far from it. Galton eventually came to recognize this and admitted that nurture begins at conception. But this posed a practical problem in greatly complicating the endeavor to separate the effects of nature and nurture. Moreover, while the concept of nature became more specific, ultimately being identified with the genome, the concept of nurture became more and more nebulously everything else. The modern label for this non-genomic everything else is “environment”. The paragon of environmental influence is still nurture in Galton’s original sense, plus accidents, but it has also been extended outward to include socioeconomic factors and inward to include the mother’s womb. The inward migration of the environment doesn’t stop at the mother’s womb. If nature is identified with the genome, then the environment must include the physiological milieu in which the genes operate, even the chemical environment of the cell. This is the focus of the science of epigenetics, according to which, much of what is called nurture not only occurs inside the skin, but also influences the effects of the genome. As we shall see, Galton’s heirs finesse this inconvenient fact in various ingenious ways. As it stands now, the nature/nurture dichotomy is a distinction between the effects of genes and the effects of everything else: genes/not genes. That does cover, logically, every conceivable developmental influence, but it is not, from a practical scientific perspective, very useful. First It crams together on the environment side a whole lot of stuff that should be carefully distinguished. That Galton felt justified in doing so was because his goal was to demonstrate the importance of nature in explaining whatever it was he felt like measuring. To do so, however, he still needed some means of separating nature from everything else, a task that even Galton came to recognize was not so simple. Let’s consider how Galton initially approached the problem.

In his book, Hereditary Genius, Galton set out to explain why some of his contemporaries were so much more successful than the common lot. More accurately, he set out to demonstrate that success was biologically inherited. To this end, he sent out questionnaires (another of his innovations) to many men of distinction in which he asked them to list their accomplishments and those of their ancestors. He found that successful men tended to have successful fathers and grandfathers. Relatively few men of distinction had poor pedigrees, by their own account. From this he concluded that the aptitude for success in any endeavor is largely inherited. He also found a high correlation between wealth and intelligence, without, however, measuring the latter.

Though Galton modestly excluded himself from the study, his intellectual son, Carl Pearson, carefully constructed a family tree from which his intellectual grandson, Cyril Burt—who infamously forged data to fit his hereditarian presuppositions--was able to account for Galton’s own remarkable career thusly: “an exceptional measure of intelligence is traceable in one or more members of every one of ten generations for whom we have first-hand information”.

Galton’s interpretation of these results did not go unchallenged. One sort of dissent made use of what scientists call a natural experiment, whose subjects were members of the House of Lords and members of the House of Commons. A Mr. Dixon compared their performance in University, and found that the elected commoners performed roughly twice as well as the unelected Lords. Galton was unimpressed, but after a gratuitous display of his statistical expertise could only muster a few anecdotes to support his claim that “the sons of peers make, it appears to me, a remarkably good show”:

            In Cambridge Mr. Strutt, the eldest son of Lord Rayleigh, was senior wrangler—that is, the very first of his year (1865), in Mathematics.; and the duke of Devonshire was second of his year in 1829. In classics, Lord Lyttleton was bracketed first, together with Dr. Vaughan  (a commoner, RCF), as the first of their year (1838), and the Hon. George Denman was the first of his year (1842). Lord Derby was one of the first class—that is, one of the first dozen or so, in 1848. In Oxford, where sons of noblemen are sent more frequently than to Cambridge, the cases are proportionately more numerous.

Thus was the nature-nurture debate begun.

Some critics focused on a methodological problem: Galton had demonstrated the inheritance of success all right but not its biological inheritance. His men of distinction inherited not only their parents’ blood but their socioeconomic privileges as well. Though this would become a major concern for later Galtonians, Galton himself could not see the merits of this argument and never tried to address it. He did though take seriously a different methodological critique, that his study failed to disprove the claim that success is strongly affected by accidental (chancy) circumstances and events that occur during the course of anyone’s life. It was to refute this argument that he turned to the study of twins.

Galton first made the important distinction between so-called identical (monozygotic) twins, which result from the splitting of a fertilized egg, and so-called fraternal (dizygotic) twins, which are produced from separate eggs that are independently fertilized and hence share only 50% of the hereditary material, the same as typical siblings. He reasoned that whatever made monozygotic twins become different, once they were separated, could be attributed to nurture. But more important, for this purpose, were the dizygotic twins. He sought to determine whether these genetically dissimilar pairs became more alike under the influence of identical nurture, living in the same home, being taught by the same teachers etc. He sent out questionnaires to the families of both types of twins, the details of which are unknown, except that one of the questions concerned anecdotes about the twins being mistaken for each other by close relatives. Oddly, all the data he reported was anecdotal; the statistician in him had gone missing.

From the anecdotes on monozygotic twins, separated after age 15 years and up, he found little evidence that their separate nurture did anything to promote dissimilarity. From the anecdotes on the dizygotic twins reared together, he found no evidence that their shared nurture did anything to lessen their dissimilarity. Galton recognized the limitations of the monozygotic twin study, allowing that their “character might have been “somewhat fixed” before they were separated, But the data from the dizygotic twins who failed to converge was so compelling that he claimed, “There is no escape from the conclusion that nature prevails enormously over nurture. His only concern was that “my evidence seems to prove too much and may be discredited on that account”. Indeed!

Galton not only framed the nature/nurture debate, he pioneered the attempt to measure the separate affects of nature and nurture. Twin studies are employed to this end to this day by his intellectual descendents. Though, as we shall see, the twin studies have become ever more sophisticated since Galton’s pioneering study, their Galtonian pedigree is beyond dispute. There is much that is problematic in this pedigree, including an obvious bias toward genetic explanations of individual and group differences. But my concern here is less with the answer that Galton gave to the nature/nurture question than with the question itself. This question, it turns out, is too simplistic to generate a meaningful answer. Though it was perfectly reasonable for Galton to pose the question, given what we now know there is no excuse to keep asking it.