Trust medical science at your peril: Correlations never prove causation

It was a long-known empirical fact that poverty, vagrancy, criminality, and apparently deficient intelligence all correlated with heredity to a considerable extent; they all ran in families and clans. The scientific confirmation that characteristics of animals are passed on from generation to generation, and the Darwin-Wallace explanation of evolution by natural selection of the fittest, made it possible to understand those aspects of human society. It was an obvious, scientifically sound conclusion that human societies could be steadily improved by restricting reproduction of the less fit and expanding the fertility of the fittest. Hence the eugenics movement, promoted by the most progressive, liberal people who were also the best educated, with an apparently justified faith in the reliability of what was at the time the most up-to-date the scientific knowledge (Trust science at your peril: Beware of scientism and political correctness). Those circumstances led to forced sterilization of tens of thousands in America and reinforced Nazis in their doctrines and practices of mass killing of the unfit — Jews, gypsies, homosexuals (Edwin Black, War Against the Weak, 2003).

Only in hindsight did the flaws and errors of the earlier scientific consensus become clear. We now appreciate that environmental and developmental influences can modify heritable traits quite dramatically. “Ill-bred” can be the result of social, economic, environmental factors as much, perhaps even more than any pre-ordained verdict of genetics; and “well-bred” individuals can spring from what might seem the least promising hereditary stock. In other words, the observed correlation between undesired social characteristics and clans was misinterpreted through neglecting the variable of environmental effects.

One lesson to be drawn is that bad science, wrong science, what some even call pseudo-science, can remain the accepted scientific consensus for decades, even in quite modern times, say, the middle of the 20^th century. It is unlikely that a mere half-a-century later our societies have become immune from assuming that a mainstream scientific consensus must be true to Nature. Nothing guards our times from treating unjustified, misguided scientific claims as good science.

Unwarranted claims coming from scientists continue to be accepted if they appear minimally plausible and if they are consistent with world-views and vested interests of financial, social, or political powers.

The most sweeping lesson that remains to be learned is that correlations must never be taken as demonstrating a cause-and-effect relationship: there might always be in play an unsuspected variable. One of the earliest axioms taught in Statistics 101 is that correlations never prove causation. The evident correlation between biological kinship and undesirable behavioral traits was not a cause-and-effect relationship.

Many or most people have never learned that basic truth that correlations are not causes. Many others “know” it as a generalization but fail to apply it in specific instances, when an evident correlation could plausibly reflect cause and consequence — just as a genetic basis for undesirable characteristics seemed quite plausible to educated and expert people not so long ago.

Indeed, a large swath of modern medical practices is based on mistaking mere correlations for evidence of causation (“Correlations: Plausible or implausible, NONE prove causation”). For example:

HPV and cervical cancer

The National Cancer Institute offers a great deal of information about this:

Human papillomaviruses (HPVs) are a group of more than 200 related viruses. . . Sexually transmitted HPV types fall into two categories:
— Low-risk HPVs, which do not cause cancer but can cause skin warts (technically known as condylomata acuminata) on or around the genitals, anus, mouth, or throat. For example, HPV types 6 and 11 cause 90 percent of all genital warts. HPV types 6 and 11 also cause recurrent respiratory papillomatosis, a less common disease in which benign tumors grow in the air passages leading from the nose and mouth into the lungs.
— High-risk HPVs, which can cause cancer. About a dozen high-risk HPV types have been identified. Two of these, HPV types 16 and 18, are responsible for most HPV-caused cancers. . . .
>> Cervical cancer: Virtually all cases of cervical cancer are caused by HPV, and just two HPV types, 16 and 18, are responsible for about 70 percent of all cases . . . .
>> Anal cancer: About 95 percent of anal cancers are caused by HPV. Most of these are caused by HPV type 16.
>> Oropharyngeal cancers (cancers of the middle part of the throat, including the soft palate, the base of the tongue, and the tonsils): About 70 percent of oropharyngeal cancers are caused by HPV. In the United States, more than half of cancers diagnosed in the oropharynx are linked to HPV type 16 (9).
>> Rarer cancers: HPV causes about 65 percent of vaginal cancers, 50 percent of vulvar cancers, and 35 percent of penile cancers (. . . .) Most of these are caused by HPV type 16.

The Centers for Disease Control & Prevention offer advice on avoiding HPV cancers:

— Bivalent, quadrivalent and 9-valent HPV vaccines each target HPV 16 and 18, types that cause about 66% of cervical cancers and the majority of other HPV-associated cancers in both women and men in the United States. 9-valent HPV vaccine also targets five additional cancer causing types (HPV 31, 33, 45, 52, 58) which account for about 15% of cervical cancers. Quadrivalent and 9-valent HPV vaccines also protect against HPV 6 and 11, types that cause anogenital warts.
— Quadrivalent and 9-valent HPV vaccines are licensed for use in females and males; bivalent HPV vaccine is licensed for use in females.
What percent of HPV-associated cancers in females and males are caused by the 5 additional types in the 9-valent HPV vaccine?
— About 14% of HPV-associated cancers in females (approximately 2800 cases annually) and 4% of HPV-associated cancers in males (approximately 550 cases annually) are caused by the 5 additional types in the 9-valent HPV vaccine.

What evidence is there for these extremely specific claims of causation?

None, actually. The cited facts are merely that the stated strains of HPV have been detected in those proportions of those cancers. Those correlations don’t begin to indicate causation.

It may be worth recalling that the Centers for Disease Control & Prevention in the early 1990s had officially stated, on the basis of the same sort of data (epidemiology, i.e. correlations), that cervical cancer was an AIDS disease, caused by HIV.

One may sympathize with medical researchers for the impossibility of conducting experiments that would be capable of proving cause-and-effect; ethical, legal, and moral restraints make it unfeasible to use human beings as experimental guinea pigs. There would also be practical barriers: To determine whether a given treatment, in this case a vaccine, actually prevents cancer, a clinical trial would be necessary that spanned over decades and enrolled large numbers of human guinea-pigs, some of whom (controls) would not get potentially-cancer-preventing vaccine.

However, the inability to obtain proof does not justify proclaiming as fact, as these official agencies do, causative relations that are no more than speculation based on statistical correlations.

[The vaccines] “Gardasil and Cervarix have not been shown to be of any significant health benefit. They have been demonstrated to cause serious injuries. It’s scandalous that they were ever approved, and it’s scandalous that they remain on the market.

And they are far from alone on those scores among new prescription medications introduced in the last couple of decades” (Deadly vaccines, 2013/04/17 http://wp.me/p2VG42-24).

Alzheimer’s Disease

Sleep disorders may raise risk of Alzheimer’s, new research shows
Sleep disturbances such as apnea may increase the risk of Alzheimer’s disease, while moderate exercise in middle age and mentally stimulating games, such as crossword puzzles, may prevent the onset of the dementia-causing disease, according to new research to be presented Monday

A daily high dose of Vitamin E may slow early Alzheimer’s disease

Again, these are correlations speculated to be possible causes.

Semantics no doubt plays a role. One could report that sleep disorders, and lack of vitamin E, seem to be associated with a risk of Alzheimer’s. Medical jargon puts it like this: “sleep disorders, and lack of vitamin E, are risk factors for Alzheimer’s”. Then the media and public conclude that “risk factor” means something that tends to cause the associated effect.

See also “60 MINUTES on aging — correlations or causes?”

Biomarkers

It is not feasible to test treatments for chronic conditions by actual outcome, because one would have to wait a couple of decades to determine whether regimen A or drug B reduces morbidity and mortality apparently associated with high blood pressure, or high cholesterol, or high blood sugar, or low bone density, etc. All those are statistically correlated with increased morbidity and mortality. They are risk factors.

Present-day medical dogma makes them biomarkers for cardiovascular disease, diabetes, bone fracture, in other words indicators of whether the disease is present. But that is tantamount to making those quantities measures of actual risk, in other words regarding them as measures of what causes those ailments, in other words equating risk factors with causes.

Official reports, however, as well as the many studies on which those reports are based, find that biomarkers are not proper measures of risk after all. See:

“Everyone is sick?”

“‘Hypertension’: An illness that isn’t illness”

“Cholesterol is good for you”

 

Unfortunately, they were not joking

“Magical statistics: Hearing loss causes dementia”

 

The overall lesson:

“Don’t take a pill if you’re not ill”

The ignorant acceptance of correlations as capable of demonstrating causation is greatly reinforced in medical matters by the pharmaceutical industry, which sells drugs as palliatives and preventatives based on nothing more than correlations with biomarkers.

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Trust science at your peril: Beware of scientism and political correctness

Science is, ideally, a quest for authentic understanding of the world, of everything in the universe. Scientism is a religious faith which preaches that only science is capable of gaining such authentic understanding and that contemporary scientific claims are for all practical purposes true.

In reality, science is a perpetually unfinished quest. The history of science tells of false trails followed, of errors made, of misguided theories held dogmatically long after the evidence had turned against them, of researchers motivated by self-interest and influenced — corrupted, in a sense — by conflicts of interest.

Science has progressed marvelously, but the progress has not come steadily and linearly, it has come through continual correction of minor errors as well as periodic scientific revolutions in which former dogmas were discarded and replaced by different theories, different beliefs, different dogmas, sometimes to an extent capable of changing world-views.

Those realities have been described and documented in many articles and books over many decades (1), yet the conventional wisdom seems ignorant of them. In the popular view, science deploys the scientific method which guarantees getting things right through scrupulous adherence to facts, so that the scientific consensus on any given topic at any given time can supposedly be relied on quite safely to guide personal and public actions.

People who question the mainstream view, the official positions disseminated by such bodies as the National Academy, the Royal Society of London, the National Science Foundation, the National Institutes of Health, the Food and Drug Administration, the World Health Organization, etc., are dismissed as ignoramuses on a par with those who still believe that the Earth is flat, and they are denigrated, attacked, and suppressed as “denialists” — for example, the eminently qualified scientists who question whether HIV really causes AIDS (2), or whether carbon dioxide is the prime cause of global warming (3), or whether the universe began in a Big Bang about 13 billion years ago (4).

In other words, the officially accepted conventional wisdom functions as an exercise of scientism, proclaiming as true — as not to be questioned — any contemporary claims that have the imprimatur of a prevailing scientific consensus.

The most common popular, mass-media-disseminated beliefs about science fall in line with the official scientistic conventional wisdom. Prominent popularizers of the scientistic faith include people sometimes described as the “New Atheists” — see for instance Curtis White in The Science Delusion (Melville House, 2014), who names among others Richard Dawkins, Daniel Dennett, Sam Harris, Bill Mahler. Self-styled “Skeptics” (for instance Michael Shermer and the late Martin Gardner) are also apostles of scientism, as illustrated in associated publications (Skeptic, Skeptical Inquirer).

But promiscuously indiscriminate faith in currently accepted scientific knowledge is unwarranted. One does not need the immense scholarly literature (1) to recognize that, it is already obvious from first principles and fundamental logic:

–>      Science is carried out by human beings and is therefore inherently fallible.

–>      Scientific theories are neither uniquely determined nor proved by any amount of factual evidence. The proverbial black swans demonstrate that no matter how comprehensive or long-standing any given body of evidence and associated explanations may be, no matter that an hypothesis may have been thoroughly tested and accepted via the scientific method, there may remain lurking in the unknown unknown some bits of data that can disprove the accepted theory instantly and devastatingly.

The popular adherence to scientistic dogmas is immensely dangerous because it may support public policies that cause tangible damage, sometimes on a large scale. Historical examples are fairly well known, but their lesson has not been learned; perhaps because a corollary of contemporary scientistic faith seems to be the notion, implicit if not explicit, that even if science was fallible in earlier times, today’s science is so advanced, so sophisticated, that it is no longer dangerously fallible. That and similar corollaries are acts of faith unsupported by evidence, thereby confirming that scientism is a quasi-religious faith: it is unshakeable, embraced as absolutely and self-evidently true.

A couple of recent books (5) describe the considerable damage done by public policies based on a scientific consensus which remained active during something like half of the 20^th century: the policies of forced sterilization of purportedly feeble-minded individuals. This was an exercise in eugenics, a program intended to improve the national genetic stock, and it was supported and justified by the prevailing scientific consensus.

In reviewing these books, David Oshinsky focuses on the Supreme Court’s 8-to-1 decision in 1927, written by the revered Oliver Wendell Holmes Jr. and agreed to by the “liberal” Jewish Louis Brandeis as well as by 6 other Associate Justices, upholding the forced sterilization of those judged to be mentally defective: “Was it an isolated misstep or something more: an indictment of Justice Holmes and the Progressive movement he appeared to embrace?” (6).

Oshinsky describes the IMBECILES book by Cohen as “a superb history of eugenics in America, from its beginnings as an offshoot of social Darwinism — human survival of the fittest — to its rise as a popular movement, advocating the state-sponsored sterilization of ‘feeble­minded, insane, epileptic, inebriate, criminalistic and other degenerate persons’.”

The point I want to make here is that the forced sterilization of tens of thousands of Americans, which continued in some States into the 1960s, is nowadays described as an outrage based on pseudo-science, yet it had relied on what was regarded at the time as perfectly sound science supported fervently by individuals whose reputation remains that of progressive reformers: as well as Justices Holmes and Brandeis, strong advocates of this eugenic program included other “progressive icons like Theodore Roosevelt and the birth control champion Margaret Sanger . . . . people who combined ‘extravagant faith in science and the state with an outsized confidence in their own expertise.’ . . . Science didn’t lie” (6).

This notion that science doesn’t lie, that it can always be believed, is a tenet of scientism, and it is baseless, quite wrong, as already noted. Yet this notion, this subconscious scientism continues to corrupt public discourse. Scientism is a faith held unwittingly by most popular media, including such elites as the New York Times; and it is held, again unwittingly, by today’s sociopolitical progressives or liberals.

When some claims by some scientists seem plausibly consistent with liberal, progressive programs, activists seize on them, make dogmas of the claims, and denigrate and attack those who disagree as unscientific denialists.

This circumstance is what has come to be called in recent decades “political correctness”: certain views are to be accepted as so self-evidently correct, objectively true — and by the way ethically and morally sound — that disagreeing with them is virtually a criminal act; and indeed actions that are politically incorrect may bring sanctions. Contemporary illustrations of such sanctions are the penalties imposed by colleges and universities on students and faculty who make politically incorrect statements, including the mere use of a word or a phrase that acts as a “trigger”, a “micro-aggression” that makes some individual belonging to a certified-discriminated-against minority feel uncomfortable (7).

That something is politically correct is shown when people who have no direct specific knowledge about a topic express with certainty a dogmatic opinion about it. They have obviously taken this opinion on faith, from sources congenial to them on ideological grounds, which may be based religiously, socially, politically — at any rate, not on actual evidence about the matter.

Contemporary scientific claims that have attained the status of politically correct include that HIV causes AIDS and that human-caused liberation of carbon dioxide is the prime cause of climate change. The manner in which media and individuals refer to these matters is an immediate proof that opinions about them are politically correct, not evidence-based.

For example, the vigilantes who most assiduously and viciously attack those who question whether HIV causes AIDS include an economist (Nicoli Nattrass), a graduate student (Ken Witwer), a psychologist (Seth Kalichman), a lawyer (Jeanne Bergman), an activist (Nathan Geffen) and others, all of whom feel qualified, despite their lack of appropriate qualifications, to denigrate eminent molecular biologists with deep knowledge of the subject, and even to demand that the National Library of Medicine remove a journal from MEDLINE (8).

Left-leaning media (say, MSNBC) treat HIV=AIDS as indisputable settled science; right-leaning media (say, Fox News) doubt that HIV causes AIDS.

Left-leaning media treat as indisputably settled science that human activities are responsible for global warming and climate change; right-leaning media doubt or deny that.

Nature, however, will not be mocked, and the truth is not determined by human ideologies. Public policies (and also private actions, of course) had best be based on the soundest, most probing and skeptical assessment of current knowledge-claims in light of the indisputable fact that no contemporary scientific consensus represents guaranteed truth.

If the present scientistic, politically correct beliefs about HIV/AIDS and about climate change are as misguided as were the scientistic, politically correct beliefs about mental deficiency and eugenics, then immense harm is being done and will continue to be done. Unfortunately, the plain evidence is that HIV does not cause AIDS (9, 10), and the notion that human activities are responsible for global warming and climate change is suggested only by highly complicated, sophisticated, and fallible computer programs that have already been wrong about the global cooling in the 1940s to 1970s and the lack of appreciable warming since about 2000 (4).

Forced sterilization as part of a eugenic program to improve the fitness of the population was supported by progressive reformers and by eminent medical and scientific experts. That physical traits are transmitted from one generation to another was known, scientifically as well as popularly. That behavioral characteristics are similarly transmitted was not obviously wrong, and when sanctioned by experts it became the conventional wisdom. So feeble-minded-ness, epilepsy, poverty, criminality and other socially undesirable characteristics came to be targets for elimination, by quarantining or sterilizing people and families where such characteristics had been noted (11). There was not sufficient dissent within expert communities to prevent what is now recognized as pseudo-science from becoming accepted as settled science, during the early decades of the 20^th century: “Less than 100 years ago, America’s finest minds were convinced the nation was threatened by sexually insatiable female morons” (12). Those finest minds included, as well as the earlier mentioned progressive reformers, David Starr Jordan, a biologist specializing in ichthyology, an activist for peace, an eminent educator — president of Indiana University and later founding president of Stanford University — and moreover so concerned with distinguishing good science from bad science and pseudo-science that he had written a book about it (13), as well as works about eugenics (14).

So policy makers might be excused for succumbing to the “scientific” evidence supporting eugenics — a century ago. Nowadays, though, there is no similar excuse for sticking with the theory of HIV/AIDS or with the claim that it is indisputably settled science that global warming and climate change are humanly caused. Competent, qualified experts have published and spoken copiously, pointing to the deficiencies of the present scientific consensuses on these matters. It is past time that these whistle-blowers, these “denialists”, be attended to; that the actual evidence be attended to.

 

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(1)    For example, among dozens or hundreds of worthwhile works:
Bernard Barber, “Resistance by scientists to scientific discovery,” Science, 134 (1961) 596-602
Henry H. Bauer, Scientific Literacy and the Myth of the Scientific Method (University of Illinois Press, 1992)
Michael Crichton, “Aliens cause global warming” (Caltech Michelin Lecture), 17 January 2003
Daniel S. Greenberg, Science, Money and Politics: Political Triumph and Ethical Erosion (University of Chicago Press, 2001) & Science for Sale: The Perils, Rewards, and Delusions of Campus Capitalism (University of Chicago Press, 2007)
Paul R. Gross & Norman Levitt, Higher Superstition: The Academic Left and Its Quarrels with Science (Johns Hopkins University Press, 1994)
Susan Haack, Manifesto of a Passionate Moderate (University of Chicago Press, 1998) & Defending Science — within Reason (Prometheus, 2003)
Ernest B. Hook, (ed). Prematurity in Scientific Discovery: On Resistance and Neglect (University of California Press, 2002)
David Knight, The Age of Science: The Scientific World-View in the Nineteenth Century (Basil Blackwell, 1986)
Thomas S. Kuhn, The Structure of Scientific Revolutions (University of Chicago Press, 1970, 2nd ed., enlarged)
Derek J. de Solla Price, Little Science, Big Science … and Beyond (Columbia University Press, 1963/1986; the 1986 edition contains additional chapters)
Gunther Stent, “Prematurity and uniqueness in scientific discovery,” Scientific American, December 1972, pp. 84-93
John Ziman, Real Science—What It Is, and What It Means (Cambridge University Press, 2000)

(2)   Henry H. Bauer, The Origin, Persistence and Failings of HIV/AIDS Theory (McFarland, 2007)

(3)    Henry H. Bauer, “A politically liberal global-warming skeptic?”, 25 November 2012

(4)    Henry H. Bauer, Dogmatism in Science and Medicine: How Dominant Theories Monopolize Research and Stifle the Search for Truth (McFarland, 2012)

(5)      IMBECILES: The Supreme Court, American Eugenics and the Sterilization of Carrie Buck by Adam Cohen (Penguin Press, 2016)
ILLIBERAL REFORMERS: Race, Eugenics and American Economics in the Progressive Era by Thomas C. Leonard (Princeton University Press, 2016)

(6)    David Oshinsky, review of (5), New York Times Book Review, 14 March 2016

(7)    A rather random selection of pieces about micro-aggression:
“Microaggression theory”; “21 Racial Microaggressions you hear on a daily basis”;
“Ten things you didn’t know were racist”; “Microaggression”; “Microaggression Theory: An assault on everyday life”; “Microaggressions: Power, privilege, and everyday life”

(8)    Letter of 5 August 2009

(9)    Henry H. Bauer, The Origin, Persistence and Failings of HIV/AIDS Theory (McFarland, 2007)

(10) Henry H. Bauer, The Case against HIV

(11) Edwin Black, War against the Weak, Thunder’s Mouth Press (2003)

(12) Farhad Manjoo, “Progressive genocide”, reviewing Better for All the World: The Secret History of Forced Sterilization and America’s Quest for Racial Purity by Harry Bruinius

(13) David Starr Jordan, The Higher Foolishness, Bobbs-Merrill (1927)

(14) David Starr Jordan, The human harvest; A Study of the Decay of Races through the Survival of the Unfit (American Unitarian Association, 1907); The Heredity of Richard Roe; A Discussion of the Principles of Eugenics (American Unitarian Association, 1911)