How To Think - and How Not to Think - About the Brain
What is "Intelligence" ?
Two recent books offer very different slants on the nature vs. nurture debate and the meaning of "intelligence"
Descartes' Error: Emotion, Reason, and the Human Brain, by Antonio R. Damasio. 1994: G.P. Putnam's Sons (324 pages, $24.95)
Who among us has not grown up believing that emotions interfere with wise decision-making, that the intrusion of feelings into our thought processes leads to irrational behavior, that the exalted workings of the brain are distinct from the mere biology of the body? In Descartes' Error, Antonio Damasio, MD, one of modern neuroscience's major thinkers, exposes the pernicious errors of our deep-seated belief in this "cartesian split" of reason and emotion in the context of an extraordinary synthesis of our current knowledge about the workings of the human brain.
Descartes' 17th century contributions to western philosophy crystallized and transmitted a dualism which remains at the roots of our culture and of our profoundest errors. "I think, therefore I am," said Descartes, and went on to assert:
"From that I knew that I was a substance, the whole essence or nature of which is to think, and that for its existence there is no need of any place, nor does it depend on any material thing; so that this 'me,' that is to say, the soul by which I am what I am, is entirely distinct from body, and is even more easy to know than in the latter; and even if body were not, the soul would not cease to be what it is."
Our abiding belief in this separation of mind from body, and of the self from the social, cultural, and physical environment of experience, has led us to invent any number of dubious entities and to locate them squarely in this "disembodied" mind: I.Q.s, mental retardation, mental illness, autism, psychosomatic disorders, and so on. By an interesting extension of this logic, our solution to many of the problems which we isolate in the mind is to remove the bearers of those minds from their social and physical environments and isolate them in institutions, hospitals, or jails.
In a tour de force of neurobiology and a tour of the regions of the brain, Damasio takes us back a century and a half to hear the story of Phineas Gage, a 25-year old railroad construction foreman who suffered an extraordinary accident: an iron tamping rod, propelled by a detonation, passed through his brain, leaving a gaping hole from side to front. Despite this catastrophe, Gage lived for another 13 years, apparently in good health and free from paralysis, with his speech, memory, and basic intelligence intact.
What did change in Gage's life is as interesting as what didn't. Originally an efficient, capable young man marked for success, the post-accident Gage became impulsive and markedly lacking in self-discipline. Seemingly unable to hold a steady job or to establish close personal ties, he became a drifter until a probable epileptic seizure felled him at age 38.
A recent computerized reconstruction of Gage's accident, based on measurements taken from his skull, was done by Hanna Damasio, MD. It revealed that the region so selectively damaged by the tamping rod was an area of the brain called the ventromedial prefrontal cortices. To understand more about how this region relates to the kinds of behaviors so markedly changed in Gage, it is necessary to find and study his living counterparts. Antonio Damasio introduces the reader to "Eliot," his young patient who, due to a brain tumor and subsequent operation, has undergone very localized damage in the same brain area as Gage. Like Gage, he too has experienced a remarkable change in personality.
Eliot had been a good husband and father, and an astute professional in a business firm. After his operation he became, like Gage, impulsive and lacking in self-discipline. He could not follow a schedule, perseverated on unimportant tasks while failing to recognize priorities, developed a passion for collecting "junk," and finally lost all his savings in a series of remarkably poor business judgements. His wife and family left, and he could no longer hold a steady job.
It is important for our understanding of "intelligence" to note, however, that Eliot's I.Q. score still tested in the superior range. His perceptual ability, past memory, short-term memory, new learning, language, and the ability to do arithmetic were intact. More subtle tests of his ability to make inferences, to make estimates on the basis of incomplete knowledge, and even a personality test designed to pinpoint dysfunction, were passed with flying colors. Yet in the personal and social realm, Eliot was lost and baffled.
Theorizing about these unusual effects of brain damage in Gage and Eliot, Damasio suggests that "there appears to be a collection of systems in the human brain consistently dedicated to the goal- oriented thinking process we call reasoning, and to the response selection we call decision making, with a special emphasis on the personal and social domain. This same collection of systems is also involved in emotion and feeling, and is partly dedicated to processing body signals." (p. 70).
The co-existence of these neural arrangements is a critical clue to the non-cartesian workings of the brain, in which "Nature appears to have built the apparatus of rationality not just on top of the apparatus of biological regulation, but also from it and with it." (p. 128). The bridge between rational and nonrational processes is emotion, a collection of body processes in response to an entity or event, and feeling, by which we "mind" or "call to mind" these body processes present or past.
Testing of Eliot and others with similar frontal lobe damage has suggested chronic difficulties in producing or becoming aware of somatic states. Necessary messages about the body, from which we derive our feelings, fail to transmit or transmit unreliably, thereby skewing the "planning and deciding" behaviors which are the foundation of the personal and social realm.
Damasio's revolutionary portrait of how reason and feelings come together in the brain has crucial implications for the study of developmental disabilities such as autism. Among the population diagnosed with autism we find people whose basic attention, memory, intelligence, and even language appear so intact that they could never be invoked to explain the autistic syndrome. And certainly few of us still believe the old myth that people with autism are simply devoid of emotion or feeling.
The explanation of autism, not unlike the explanation of Phineas Gage's unusual neuro- psychological profile, may lie within the brain's delicate mechanisms for linking logic and emotion and biological feedback. When these mechanisms are compromised and their workings unpredictable, the result may be manifested as a sensorimotor disturbance. The person may experience chronic difficulties in keeping body movements regulated and controlled, and in synchronizing interactions to meet the personal and social requirements of other individuals.
Although the lion's share of Damasio's research has concerned individuals with brain injuries, in the late 70s and early 80s he and Ralph Maurer, MD, published research suggesting that autism involves disturbances in the initiation and execution of spontaneous movements (Damasio and Maurer, "A neurological model for childhood autism," Archives of Neurology, Vol. 35, 1978; and Maurer and Damasio, "Childhood autism from the point of view of behavioral neurology, JADD, Vol. 12, No. 2, 1982). These groundbreaking studies have inspired the recent efforts of other researchers to track the social and emotional implications of these movement difficulties.
The testimony of many people with autism, most recently the popular autobiographies of Donna Williams, suggests enormous difficulties in reliably calling forth, regulating, and "reading" emotions, and therefore in translating them into the appropriate feelings. The same difficulties arise when Temple Grandin walks with Oliver Sacks under the Colorado night sky. As she explains, "When I look up at the stars at night, I know I should get a 'numinous' feeling, but I don't. I would like to get it. I can understand it intellectually. I think about the Big Bang,and the origin of the universe, and why we are here: Is it finite, or does it go on forever?" Sacks persists, "But do you get a feeling of its grandeur?" But the question seems baffling. "I intellectually understand its grandeur," she replied..." ("An Anthropologist on Mars," The New Yorker, December 27, 1993, p. 124).
Similarly, Eliot tells Damasio "without equivocation that his own feelings had changed from before his illness. He could sense how topics that once had evoked a strong emotion no longer caused any reaction, positive or negative." (p. 45). As Damasio suggests, when the mechanisms for processing such vital information go awry, there can be little wonder over the resultant difficulties in judging and carrying out adaptive social behaviors.
Not only does Damasio succeed in deflating the current reification/ deification of I.Q.-measured "intelligence" by proposing a subtler version of rationality which resists separating mind from body, he also resists the temptation to separate mind and behavior from society and culture:
"Only a part of the circuitry in our brains is specified by genes. The human genome specifies the construction of our bodies in great detail, and that includes the overall design of the brain. But not all of the circuits actively develop and work as set by genes. Much of the brain's circuitry, at any given moment of adult life, is individual and unique, truly reflective of that particular organism's history and circumstances. Naturally, that does not make the unravelling of neural mysteries any easier....(In addition) each human organism operates in collectives of like beings; the mind and the behavior of individuals belonging to such collectives and operating in specific cultural and physical environments are not shaped merely by the activity-driven circuitries mentioned above, and even less are they shaped by genes alone. To understand in a satisfactory manner the brain that fabricates human mind and human behavior, it is necessary to take into account its social and cultural context. And that makes the endeavor truly daunting." (p. 260).
Descartes' Error itself is a daunting endeavor and also a work of true science, one which seeks to trace the shapes of our constraints as well as the open windows and doors through which growth and change, the "individual and unique," continually proceed.
The Bell Curve: Intelligence and Class Structure in American Life, by Charles Murray and Richard J. Herrnstein. 1994: The Free Press (845 pages, $30)
Comparing Descartes' Error to The Bell Curve is a bit like comparing a nourishing, soul- satisfying Thanksgiving dinner to a Big Mac. The Big Mac may be n well, big n but its contents are neither elegant nor well-balanced.
The Bell Curve supposedly documents the contention that race and class differences are largely genetic in origin, being directly correlated with a single factor called "intelligence," and are therefore immutable. Far from being a fresh concoction, this thesis is simply a stale rehash of nineteenth-century Social Darwinism.
Social Darwinism offered a moral justification for class stratification and inequality in newly industrialized societies on the theory that genetically inferior people would inevitably sink to the bottom of the social system, making a permanent underclass a necessary evil. In culture as in nature, it was argued, the fittest would survive and perpetuate their "good" genes, while the unfit must be allowed to perish or at least encouraged not to reproduce, lest the entire social "stock" be weakened.
Stanford psychologist Lewis M. Terman ushered Social Darwinism into the 20th century when he imported Alfred Binet's academic readiness test from France, developing it into the Stanford- Binet I.Q. test. From the start, Terman interpreted this test on a hereditarian basis, a possibility from which Binet himself had steadfastly recoiled.
Through I.Q. testing of immigrants, who often could not speak the language in which the test was given, and poorly- conducted mass testing of army recruits, Terman and his colleagues identified a number of populations they believed to be intellectually inferior, including people of southern and eastern European descent. Later in the century, Terman's hereditarian interpretation of I.Q. testing found an outspoken champion in Richard Herrnstein, co-author of The Bell Curve. In a highly controversial 1971 article in The Atlantic Monthly, Herrnstein (who died in 1994) began to focus the hereditarian argument on the I.Q. scores of African-Americans. It is this focus which Herrnstein and Murray develop in The Bell Curve: the "dull" people caught at the bottom of the social ladder in a web of "socially undesirable behaviors" are represented as disproportionately "black."
As evolutionary biologist Stephen Jay Gould has pointed out, the Herrnstein-Murray argument in The Bell Curve rests on four assumptions: that "intelligence" is a unitary entity that can be measured by a number; that people can be ranked in linear order according to their numbers; that this numbering and ranking has a true genetic basis; and that nongenetic factors (environment, culture, nutrition, etc.) have no overall effect.
What Murray and Herrnstein conveniently fail to mention is that their central assertion of a single general cognitive ability finds little professional support. Gould himself debunked its spurious statistical basis in his classic 1981 study, The Mismeasure of Man. Researchers such as Howard Gardner (Frames of Mind: The Theory of Multiple Intelligences, 1993) have developed extensive evidence for an array of different kinds of intelligences which seem to function with remarkable independence from each other.
The ranking of entire groups on the basis of "general cognitive ability" becomes even more bizarre when we consider how genetically mixed the world's peoples really are, with "black," "white," or "Asian" more akin to cultural or folk categories than biologically separate populations. As for The Bell Curve's assumption of a genetic basis of intelligence which is impervious to nongenetic factors, it is worth remembering that among the high I.Q. scorers in Murray and Herrnstein's new "cognitive elite" are the descendants of many of those same Eastern European immigrants deemed intellectually unfit by Terman's earlier intelligence test.
Murray and Herrnstein's 845-page immersion in old-fashioned and highly-debatable assumptions from psychometrics and population genetics seems to have blinded them completely to the substantial contributions to our understanding of "intelligence" coming from the new field of cognitive neuroscience. This oversight is inexplicable at a time when the work of neurologists such as Antonio Damasio is yielding scientifically elegant and compelling data on the intricate development and variation of human brain systems.
Damasio's discoveries about how and why different kinds of reasoning and competencies exist lend further evidence to the theories of independent "multiple intelligences." Moreover, neuroscience's new understanding of the subtle and varied forces which shape the human brain and human behavior makes Murray and Herrnstein's claim to have resolved the "nature vs. nurture" debate about as nonsensical as it would be to hear a modern chemist announce that he has resolved the polarities of earth, air, fire and water: these long ago ceased to be meaningful ways to conceive of how nature works.
Damasio has stated the true, and far more complex, developmental dynamic which challenges modern brain researchers: "(A)s we develop from infancy to adulthood, the design of brain circuitries that represent our evolving body and its interaction with the world seems to depend on the activities in which the organism engages, and on the action of innate bioregulatory circuitries, as the latter react to such activities. (Descartes' Error, p. 111, emphasis in the original). In other words, we cannot understand the brain as an isolated, immutable structure; rather, it is part of a larger, constantly evolving feedback loop of individual activity and circumstances, reaction and self-regulation. It is difficult to know what to say about a book on a complex topic like "intelligence" which ignores the revelations of cognitive neuroscience, ignores the brain itself, ignores memory, and even ignores learning, yet those words do not even appear in The Bell Curve's index!
These oversights become explicable when we realize that The Bell Curve is an exercise in "scientism," the pretense of science in the service of other ends. To understand how this stale rehash came to be served up with such a fanfare of publicity, it is enlightening to identify its financial and political sponsors.
In the late 1980s, when Charles Murray began to delve seriously into the possibility of drawing a connection between race, intelligence, and social class, his research came to be viewed as an embarrassment by many previous supporters. His employer, the conservative Manhattan Institute in New York, suggested that it was time for Murray and his project to move on. He found a new home at the American Enterprise Institute in Washington, D.C., and a new funding source in the Milwaukee- based Bradley Foundation, a major funder of conservative institutions such as the Heritage Foundation, which paid Murray nearly $1 million over the past eight years to produce his book.
Also of significance is The Bell Curve's connection to the pro- eugenics Pioneer Fund, which sponsored much of the research on which Murray and Herrnstein's arguments rely. The Pioneer Fund is a little-known group founded in 1937 to promote research on "the problem of heredity and eugenics" and to encourage the reproduction of descendants of "white persons who settled in the original 13 colonies prior to the adoption of the Constitution and/or from related stocks." In 1985 the word "white" was deleted from its charter, but the fund's focus remains the same. In recent years the Pioneer Fund has sponsored the work of pro-eugenics researchers such as Arthur Jensen and William Shockley, who attained notoriety over his proposal that the government pay people with low I.Q. scores to be sterilized.
Like many of the researchers on whose work their own is based, Murray and Herrnstein are scarcely disinterested scientists. The final chapters of The Bell Curve, which recommend specific political policies, undoubtedly account for the success of a book which may not contain anything new, but which is perfectly timed to ride the crest of the current political resurgence of Social Darwinism.
Those concerned with education will note that The Bell Curve advocates a shift in thinking and in funding away from the "disadvantaged" and toward the "gifted": "Specifically, critics of American education must come to terms with the reality that in a universal education system, many students will not reach the level of education that most people view as basic." (emphasis in the original). Policy makers, The Bell Curve suggests, have to stop kidding themselves about the efficacy of educational and social programs designed to equalize a class system shaped by immutable differences in intellectual capacity. The business of the "cognitive elite" is to help people fit into society on the basis of their proper place in the I.Q. hierarchy, lest the elites eventually be required to maintain a "custodial state" to keep the improvident underclass from swamping civilization.
What a vision, not only for racial and ethnic minorities, but for those of us with disabilities who would all too readily be assigned our proper lifetime slots on the basis of the usual criteria. The seductive but spurious rationality of a world ordered "by the numbers" is another product of Descartes' error: Murray and Herrnstein's bizarre vision results, not from a defect in logic, but from a defect in the emotions and feelings that inform true rationality. Surely any intelligence test in which high scores can be achieved by people who share this vision is dangerously flawed.
As Stephen Jay Gould concluded in his review, "Curveball" (The New Yorker, Nov. 28, 1994), "We must fight the doctrine of The Bell Curve both because it is wrong and because it will, if activated, cut off all possibility of proper nurturance for everyone's intelligence." ??