Inequality kills

Two books in the last decade have drawn attention to the health implications of inequality in society, The Status Syndrome1 (Michael Marmot, 2005) and The Spirit Level2 (Richard Wilkinson and Kate Pickett, 2009). Politicians have paid lip service to their revelations but the inequality has continued to grow. Michael Marmot’s new book, The Health Gap, has just been published and will be reviewed as soon as I’ve finished reading it. This review sums up the evidence so far.

In 2008, the WHO3 reported that life expectancy not only varied widely between countries (a girl in Lesotho has a life expectancy 42 years less than one in Japan) but within countries also (children born eight miles apart in the Glasgow area have 28-year differences in life expectancy). These facts come from the report of the WHO’s Commission on the Social Determinants of Health, a three-year investigation whose findings are truly shocking.

One commission member was Michael Marmot, Professor of Epidemiology and Public Health at University College, London. He has been involved in one of the longest-running studies of the health of workers, the Whitehall Studies, following civil servants’ health since 1967 (male workers) and 1985 (both male and female). This and many other studies throughout the world reveal a “social gradient” in health. We might expect the poorest sections of society to have worse health than the well-off but Prof Marmot shows in his book The Status Syndrome that the picture is rather more complex.

He shows that the social gradient in health is only partly due to absolute poverty. Also, it is only partly due to more unhealthy behaviours. His findings are the same as but predate those of the more well-known book The Spirit Level. Both conclude that it is our relative level in society that is crucial. Put simply, Marmot concludes that we all live in hierarchical societies and where you are in the hierarchy, at work or in society in general, affects your health. This is still true even after taking all other factors into account.

Now, in different societies, or in the same society at different times, different diseases are prevalent. In 19th century Britain, tuberculosis was a widespread killer: nowadays, it’s heart disease. But there is a social gradient in both. Then, 16% of gentlemen were “consumptive”, while 30% of labourers were. Tradesmen were in between at 28%. Now, heart disease affects those lower down in the hierarchy more than those in the next rank…and those in the next rank… and so on. The Whitehall studies divided civil servants into Admin, Executive, Clerical and Other. The last group, porters, doormen, drivers and so on, had the greatest risk of dying of coronary heart disease (CHD); then came the clerical staff; then the executives; and lastly the senior, administrative, grades. The lowest grade had an 80% higher chance of dying from CHD than the top grade. They also had the highest rates of smoking, blood cholesterol, blood sugar and raised blood pressure, all consequences of unhealthy eating. But, crucially for Prof Marmot’s argument, the health gradient persisted even after these were taken into account, the lowest grades still having a 50% higher chance of death from CHD.

The same pattern is found in the whole population: life expectancy increases steadily from Class V (lowest) to Class I. Of course, as health treatment has improved and people have become more health-conscious, life expectancy has increased. For men in England and Wales, Class V life expectancy increased from 65.5 to just over 68 in 20 years (between 1972-6 and 1992-6): for Class I, it rose from 72 to 77.5. But, while life expectancy rose for everyone, the health gradient not only persisted but even got steeper over a period that included Thatcher and her attacks on unions and workers’ rights.

There are a whole lot of social gradients which nearly all mirror the health gradient. They include education, social class of parents, job prestige, and income (The Spirit Level goes into more examples, like social mobility, violence or women’s status). Do these cause the health gradient? Or is it the other way round? Do one’s genes explain it? Marmot goes to great lengths to tease out the chain of causality.

While unequal access to health care is no doubt a factor, Marmot shows that it does not explain the health gradient. The Whitehall Studies showed that there was a social gradient in the incidence of disease (i.e. first occurrence, before health care was involved). In any case, thanks to our health service, civil servants received appropriate levels of health care. A similar social gradient was later found in women, despite the different ways that social status might be attributed.

So what explains this? For a scientist, it not enough to show a statistical relationship between two things. Does one cause the other – or is there a third factor that explains both? And the answer has implications about what, if anything, should be done. It is simplistically thought that it’s merely a matter of money – or of lifestyle choices. Marmot quotes a colleague reviewing the evidence for the social gradient in health as coming from two studies of free-living primates: British civil servants and baboons in the Serengeti! As Marmot points out, baboons don’t have money and neither do low-ranking baboons smoke, consume junk food, or fail to attend doctor’s appointments. But like civil servants, they do have a social gradient in health which mirrors their position in the hierarchy of baboon society.

Does this mean that, since hierarchies naturally form in primate societies, the health gradient is a fixed fact, determined by evolution? No, says Marmot. Hierarchies are a fact but “what it means to be high and low in a hierarchy varies”. Biology and society are interacting and can interact differently in different situations. In money-based societies, it is the relative income that reflects one’s status. This shows in self-report of happiness, with richer societies such as USA reporting no change in happiness in a period where the economy grew by 50%.

If it is not absolute income that determines happiness, what does? Or, more to the point, what is it about one’s position in a hierarchy that ultimately gives rise to the health gradient. Marmot identifies the degree of control one has over one’s life circumstances as the key factor, with stress as its inverse. There are five aspects to this – “control, predictability, degree of support, threat to status, and presence of outlets” – which can modulate the effects of a psychological threat. Marmot illustrates this with a hypothetical low-paid working couple, already poor, one of whom loses his job, becomes depressed and starts drinking, instead of helping to look after the children. The other’s job is also under threat as the factory she works in is being undercut by cheaper imports. Both face loss of status if they end up on benefit. Outlets to relieve the stress would cost money they no longer have. The boss, in this example a caring individual who does not want to lay off staff, may have to move production off-shore. He however has his community work which enhances his status, his support from a wife with a professional job, and his outlet of golf.

Can lack of control or power over life cause illness? Marmot gives diverse examples to show that it can. In 1981, a major earthquake struck Athens. The death rate from heart attacks shot up by 50% over three days. In 1991, in the Gulf War, Iraq bombarded Tel Aviv with Scud missiles. During the first week, heart attacks increased significantly. In 1996, 60% of the Dutch population saw on TV their team lose on penalties to the French in the European football championships. The rate of deaths from heart attacks and stroke on that day rose by 50% in men (but not in women).

Marmot as a scientist is not satisfied with the vague diagnosis of “stress” causing these excess deaths or the other health problems linked with status. He wants to understand how external factors (“control, predictability, degree of support, threat to status, and presence of outlets”) “get into” the body and cause illness. Here he refers to Robert Sapolsky’s studies of stress in animals on the East African savannah. Sapolsky describes a lion chasing a zebra, a life-and-death situation for both. Energy release must be maximised so that the muscles can work best. The sympathetic nervous system is activated and hormones released to increase heart rate, blood pressure and blood glucose levels. Unnecessary activities, energy storage, digestion (hence a dry mouth), growth, reproductive functions, inflammatory responses, tissue repair and immune response, are postponed.

Referred to as the “fight or flight” response, these changes involve release of the hormones adrenalin and cortisol. Adrenalin increases heart rate and breathing rate, and causes release of glucose from the liver and in the muscles. Cortisol suppresses the immune system, increases glucose levels in the blood, and suppresses inflammatory responses. This is appropriate for an immediate threat but, maintained over a long time, has the following effects. Insulin’s action is inhibited, risking diabetes; fat is deposited round the waist, rather than the hips; there are low levels of “good” cholesterol; blood pressure is high: these changes are associated with developing CHD. Marmot comments that, in people with CHD, acute stress, such as an earthquake or losing a football match, could easily trigger a fatal heart attack or stroke. To show the link, he refers to studies on rhesus monkeys, social primates that form hierarchical groups.

The monkeys were fed a diet high in saturated fats and cholesterol, known to cause atherosclerosis, narrowing or “furring up” of the coronary arteries that supply the heart muscle with blood, However, not all the monkeys developed atherosclerosis: those of lower rank were significantly more likely to get it. And this was only due to their rank as was shown by changing their groups: when top ranking monkeys were put in a group by themselves, a new hierarchy developed and those now lower down started developing atherosclerosis. Studies on baboons found that low ranking ones had higher cortisol levels and lower “good” cholesterol levels in their blood. Measurements were taken after shooting the baboons with tranquiliser darts. Marmot remarks that they decided not to “dart” civil servants but were able to show that, the lower the grade of job, the lower was the level of “good” cholesterol, the higher the blood glucose, and the more fat round the waist, changes linked to high levels of cortisol and predisposing people to CHD and diabetes.

Clearly, status affects health and the steeper the differences in status the more health is affected. Broadly, this is the same thing as inequality and, in The Spirit Level, it is pointed out that in both UK and USA inequality, as measured by the difference in incomes between richest and poorest, increased greatly in the 1980s. It is no exaggeration to say that the attacks on workers’ rights spearheaded by Thatcher and Reagan which have persisted until now are responsible for a great deal of disease and death.

Now Cameron’s government is cutting benefits and demonising claimants. Does the lesson of this need to be spelt out? Thus it would seem!

1Michael Marmot. Status Syndrome: How Your Social Standing Directly Affects Your Health. Bloomsbury, 2005.

2Richard Wilkinson and Kate Pickett. The Spirit Level: Why More Equal Societies Almost Always Do Better. Allen Lane, 2009.



M-theory and “The Grand Design”

[This is updated from when I first wrote a review of Hawking and Mlodinow’s book. M-theory seeks to unify all string theories. So far, no practical verification of the predictions of M-theory have been forthcoming, leading Peter Woit and others to describe string theory as “not even wrong.” On the other hand, Nima Arkani-Hamed describes string theories as “like democracy, the worst idea except for everything else.”]

Stephen Hawking’s book, The Grand Design,1 written with physicist and author Leonard Mlodinow, seeks to answer questions that many have asked:

Why is there something, rather than nothing?

Why do we exist?

Hawking and Mlodinow (H&M) also pose a question which potentially answers the first two:

Why this particular set of laws and not some other?

The answer, say H&M, is to be found in M-theory.2

The trivial answer to the last question is that, if the laws were different, we would not exist and would not be asking any questions. But the observed laws seem to be very finely tuned to allow matter to exist in extended forms, like atoms, molecules and us. This has been called the anthropic principle and, in its strongest form, has often been given as circumstantial evidence in favour of design, allowing god to slip back in after being excluded from all other observed processes.

H&M controversially argue for a strong anthropic principle: “the fact that we exist imposes constraints not just on our environment but on the possible form and content of the laws of nature themselves”. However, their argument does not rely on a grand designer but on the possibilities inherent in M-theory.

M-theory is an attempt to unify all of the forces of nature into one overarching explanation, encompassing the very large and the very small. The reason for trying to do this is not just a love of orderly explanations but that previous unifying theories, that which unified the electric and magnetic forces in the 19th century, that which included quantum mechanics (quantum electrodynamics – QED) and that which unified the weak force with the electromagnetic (EM) force (the Standard Model) in the 20th century, led to enormous benefits. Promising attempts to unify the strong force with the EM and weak forces have been made (Grand Unified Theories – GUTs). M-theory is an example of a Theory of Everything (ToE) which aims to include the gravitational force.

Why the urge to unify or to build more inclusive theories? This sounds like the sort of “blue skies” research that politicians scorn, in favour of research with commercial benefits. However, the work of James Clerk Maxwell in the 19th century to uncover the relation between electric and magnetic fields, curiosity-driven, showed that electromagnetic fields spread through space at the speed of … light! Thus, light was an electromagnetic wave, which led to the discovery of radio waves, microwaves, X-rays, gamma rays, and to untold benefits in medicine and communication. It is quite reasonable (though not guaranteed!) that future unifying theories will lead to useful outcomes.

H&M’s approach leans heavily on the work of my favourite scientist, Richard Feynman, a profound thinker but also an engaging and playful character. You would be rewarded if you looked into his life (and perhaps watched clips of interviews with him on the BBC website).

Feynman worked on the science of the very small, where quantum effects rule. One example concerns the behaviour of light when it shines on two vertical narrow slits very close together. This gives rise, not to two vertical bars on a screen, but to a wide horizontal band of dark and light bars.

This has classically been explained (by Thomas ‘Phenomenon’ Young, another fascinating character) as the interference of the peaks and troughs of waves, sometimes reinforcing, sometimes cancelling each other, much as ripples in water do. This fatally wounded the particle theory of light held by Newton.

This common-sense explanation was however shown to be inadequate, not least by the proof by Einstein that light could act as particles, photons, in the photoelectric effect. Newton’s theory rose again Lazarus-like. More oddly, when faint beams of light consisting of single photons are shone on a double slit, the interference pattern supposedly explained by wave behaviour is gradually reproduced, spot by spot!

The “solution” was to associate a probability wave with each photon so that where it ended up was essentially random but over time a distinct pattern emerged. It was as if each photon passed through both slits and the probabilities interfered with each other resulting in the detection of the photon at a particular place.

Theory predicted that matter particles would also have a probability wave associated with them and, sure enough electrons (and larger particles) behave in a similar way with a double slit – even single electrons interfere with themselves (this experiment was voted the most beautiful experiment in physics in 2002)! [see foot of post]

Feynman’s explanation is that the system, in this case the single electron/double slit/screen system, has not just one but every history. The particles take every possible path on their way from the source to the screen – simultaneously! Furthermore, our observations of the particles go back into their past and influence the paths they take.

If, like me, you’re going “What?”, you’re in distinguished company: Feynman himself said “I think I can safely say that nobody understands quantum mechanics”. Nevertheless, the theory has passed every test.

Lots of people are unhappy with the implication that someone has to be looking before a quantum process is “forced” to arrive at a particular outcome – and yet this has been confirmed by many experiments. It actually is the case that the outcome is influenced by the process of measurement or “detection” (though this need not be a conscious process – I prefer the idea of an interaction causing the quantum process to reach a conclusion).

This sort of crazy quantum behaviour obeys strict laws. Laws of nature are not like human laws which seek to encourage certain preferred behaviours. They explain how things behave and how they can behave. The laws of modern physics, including the modern understanding of gravity, explain an incredible range of observations to incredible precision and have made amazing predictions which have almost entirely been borne out. H&M pose more fundamental questions, including “Is there only one set of possible laws?”

The laws are, needless to say, not entirely known. While three of the four forces of nature, the electromagnetic, weak and strong forces, have provisionally been united in the “standard model”, crucially gravity still needs to be integrated into the picture. This what M-theory, incorporating string theory and supergravity, seeks to do. One of its startling predictions is that there are 10 space dimensions and one time dimension, in contrast with our everyday experience of three space dimensions and one time. The unobserved dimensions are rolled up very small, so that particles are actually vibrating strings or membranes.

M-theory does not predict the exact laws observed. These depend on how the extra dimensions are “rolled up”. A great many universes are possible, some 10*500 or 1 followed by 500 zeroes, each with a different combination of fundamental constants, and it is not surprising that we exist in one where the constants are compatible with the evolution of life. The “apparent miracle” is explained.

H&M point out that the law of gravity is not incompatible with the emergence of a universe “from nothing”. In particular, the principle of conservation of energy is not violated (because, while matter energy is positive, gravitational energy is negative) and, at least in quantum mechanics, what is not forbidden is compulsory. Furthermore, with a wide range of possible sets of constants, some (at least one!) universes must come into existence in which life can evolve. And here, without the need for a creator, we are!

1 Transworld Publishers, 2010. ISBN: 9780553819229

2 A fairly(?) simple explanation can be found here:

Double slit - single electron diffraction experiment
Double slit – single electron diffraction experiment

“Doctors of the Dark Side”

[I wrote this a couple of years ago after seeing this film, which was released in 2011. Since then, the BBC covered some of this area in

The Secret War on Terror (World Service) Aug/Sep 2011

and Panorama: Fighting Terror with Torture (BBC1) 7 Aug 2015

both still available. Recently, the extent of the collusion of the American Psychological Association with the Bush administration was revealed. I will deal with this in a subsequent blog.]

DODS: Medical personnel in the US torture programme

Western democracies have prided themselves in applying humane standards to the treatment of prisoners of war. This treatment is encapsulated in the Geneva Convention, first formulated in 1864 and modified since, most recently in 1949.1 They have also signed up to the UN Convention against Torture.2 Undoubtedly, these conventions have been flouted by some democratic states (France in Algeria, Britain in Northern Ireland, USA in Vietnam, …). However, the US explicitly banned torture and harsh treatment by military interrogators after the Vietnam war, introducing the Army Field Manual on Interrogation (FM 34-52)3 in 1992. However, in recent years, the US has subjected captives to treatment which had previously been recognised as torture or, at least, as inhumane. A particularly disturbing aspect has been the involvement of medical professionals, doctors and psychologists, in advising or agreeing to such treatment.

This is the subject of the documentary film (by Martha Davis) Doctors of the Dark Side4. This important film received its first UK showing on 29 October 2013 at University College London. Over 300 people attended the screening and the discussion that followed, including contributions from the film’s director, who had flown from the US specially for the showing, and from Philippe Sands and other human rights activists.

Intriguingly, the film opened with the case of US Navy Petty Officer Daniel King. In 1999, he was working as a cryptanalyst when a routine polygraph (“lie detector”) test proved “inconclusive”. He was then subjected to extensive interrogation, including 29 days of sleep deprivation (described as torture by AFM 34-52) to get him to admit to spying. This had the effect of so confusing and disorienting him that he thought he must be guilty but had “forgotten” the details. Crucially, a psychologist working for the navy, Michael Gelles, was shown trying to get King to admit to something, while King asked him for help in recalling the “memory” he thought he had lost. Gelles had forgotten that his responsibility was to his patient and that he should “first do no harm”. (Later, Gelles turns up at Guantamo Bay where he plays a rather more honourable role in exposing abusive interrogation practices.)

Complicity of medical personnel in torture was a key feature in interrogation of suspects in the “war on terror”. Psychologists in particular helped to develop a programme of techniques to “break down” suspects. Leading these were Drs Bruce Jessen and James Mitchell who took as their guide the SERE programme. Survival, Evasion, Resistance and Escape was designed partly to help US armed forces members to resist abusive interrogation, including torture. They reverse-engineered the programme to come up with enhanced interrogation techniques (EIT) that would be used on Al Qaeda suspects … and anyone else who happened to be in the wrong place when people were rounded up. Perhaps 85% of prisoners at Abu Ghraib were innocent. The problem that EIT amounted to torture was solved by simply asserting the opposite! The problem that these techniques typically produce useless or untrue information and false confessions was ignored. The problem that EIT psychologically damaged victims, many innocent, permanently was also ignored. And so was the problem that any admissions made could not be used in a court of law.

The film shows some of the abuse of prisoners by soldiers at Abu Ghraib to set the scene and then shows staged examples of some techniques: sleep deprivation, extreme isolation, enforced nudity, sexual humiliation, extremes of temperature, loud noise, bright light and darkness, confinement in a cage or tiny box, the use of uncomfortable stress positions, slamming into a specially-built plywood wall, and of course waterboarding or simulated drowning. Doctors would be on hand to monitor blood pressure, pulse rate and blood oxygen levels, and to authorise interrogation to continue. They were not protecting their “patients” but allowing them to be abused up to the time where their lives might be in danger.

Dissenting doctors, psychologists and psychiatrists are interviewed in the film (supporters of EIT were not available!). One of these is retired Brigadier General Dr Stephen Xenakis, a top army psychiatrist, who states that it is “extremely cruel to keep someone awake – they will have psychotic-like thinking, they will be very disorganised and … very unreliable.” Thus what is “the single greatest scandal in the history of American medical ethics” unfolded, where doctors were “the centrepiece of torture”, devising methods of torture that “do not leave wounds” and supervising their use, “keeping alive those that are meant to be kept alive”. One military psychologist is quoted: “If producing some pain does the most good for the most people, it’s entirely ethical.” However, as Nathaniel Raymond (Physicians for Human Rights Campaign Against Torture) points out, “When people committed these same acts, we prosecuted them in the past in places like Nuremburg. What’s different here?”


1Article 3: “Noncombatants, combatants who have laid down their arms, and combatants who are hors de combat (out of the fight) due to wounds, detention, or any other cause shall in all circumstances be treated humanely, including prohibition of outrages upon personal dignity, in particular humiliating and degrading treatment.”

2UN Convention against Torture (and Other Cruel, Inhuman or Degrading Treatment or Punishment): Definition of torture “Any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him or a third person, information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity.” 3 4

Interrogating terrorists

Terrorism exists and, regardless of any blame due to the US or other governments for encouraging it by their actions, we have an interest in not being blown up. And, like it or not, the security forces, police and military, are the main defence we have. Would that it were otherwise! Surely we therefore want terrorist prisoners to tell us what they know about their plans to murder us. If this includes “enhanced interrogation techniques” (Bush government) or “torture and cruel, inhuman or degrading treatment” (UN Convention against Torture) surely this would be justified. This is a scientific question!

The answer is “No,” according to leading military interrogators in the US itself!

One of these, FBI agent Ali Soufan, testifying to the Senate Committee on the Judiciary in 2009, stated that using conventional non-coercive techniques he had got useful information from an al Qaeda operative, Abu Jandal, straight after reading him his rights. He works by building a relationship with the detainee who, isolated and fearful, eventually comes to rely on him as someone he can talk to and who will listen to him. Acting in a non-threatening way in itself confuses the detainee who has been led to expect the opposite. Then, as the interrogator, Soufan would impress the detainee with the evidence already known against him. The interrogator has to do his “homework” on this evidence and make the detainee feel that lies will be identified quickly. Clearly, this is a lot more difficult and requires a lot more skill than simply humiliating and brutalising someone but, Soufan shows, it gets more, and more truthful, information and often more quickly than coercive techniques which, in any case, al Qaeda terrorists are trained to resist. [This was described four years ago in an interview in the BBC’s “The Secret War On Terror”

Soufan argues that harsh techniques are expected by the terrorist prisoner but also that the information gained is unreliable. The process is slower, too: sleep deprivation for 180 hours obviously takes … 180 hours, while waterboarding Khalid Shaikh Mohammed 183 times took months and did not provide useful information (but did provide false information). Almost as an afterthought, Soufan reminds us that information gained by torture or other harsh methods is not admissible in courts of law.

The contrast between the two approaches is exemplified by the case of Abu Zubaydah. Within an hour, Soufan and his FBI colleague got useful information from Zubaydah and continued to do so. For ideological reasons, the CIA was ordered to take over and, with the assistance of “private contractors”, used enhanced techniques. The intelligence dried up. Soufan was asked to return and the intelligence started coming again. The pattern of alternation continued with the same results until Soufan, his colleague, and a psychologist refused to be party to this ill-treatment any longer.

Another interrogation expert, retired Brigadier General David Irvine, speaking to a bi-partisan panel looking into the use of torture by US forces, stated that “going to the dark side” yielded no useful information that saved the “hundreds of thousands” of lives claimed by Bush and his colleagues. In fact, the US had been “badly misled by false confessions … derived from brutal interrogations”.

As an interesting observation, the enhanced techniques were based on milder forms of ill-treatment used on trainee US soldiers to help them withstand such treatment from Stalinist captors (e.g. in Korea or Vietnam). And such treatment was originally developed by the Stalinists as “brain-washing” to elicit not truth but false confessions for propaganda purposes.

One false confession that had unfortunate consequences was by Ibn al-Sheikh al-Libi, a jihadist from Libya. He was co-operating with FBI interrogators using legal techniques but the CIA felt he had more to tell and sent him to Egypt to be tortured. He then falsely claimed that Saddam Hussein had met al Qaeda members to discuss nuclear weapons. He said later that he was pressed to talk about biological weapons as well but, as he knew nothing about them, was unable to come up with a plausible lie. This “information” about links between Iraq and al Qaeda was then used by Colin Powell as part of the justification for the invasion of Iraq.

Soufan’s techniques come straight out of the US Army Field Manual on Interrogation (FM 34-52). This notes, among other things, that “physical or mental torture … [as] illegal acts are not authorized and will not be condoned by the US Army. … Experience indicates that the use of prohibited techniques is not necessary to gain the cooperation of interrogation sources. Use of torture and other illegal methods is a poor technique that yields unreliable results … and can induce the source to say what he thinks the interrogator wants to hear. … Revelation of the use of torture by US personnel will bring discredit upon the US … [and] may place US and allied personnel in enemy hands at a greater risk of abuse by their captors…”

These comments are an accurate prophecy of what happened when the Bush government junked 34-52 and allowed the practice of what 34-52 explicitly described as physical (stress positions) and mental (sleep deprivation) torture.

False confessions

Many people falsely admit to committing crimes or falsely accuse others. There are many reasons for their doing this but a very powerful one is to get torture or harsh treatment to stop. The Innocence Project in the US has been instrumental in getting more than 300 serious criminal convictions overthrown, often through use of DNA evidence not available or suppressed at the time of conviction. They report that in a quarter of these cases the innocent person had actually falsely confessed to the crime after threats or other coercion.

Such treatment was used by Stalin to get many political opponents and other innocent people to confess to grotesque crimes, starting with the Moscow ‘show trials’ of 1936. Under the influence of beatings, forced standing, sleep deprivation, and threats to family members, virtually all of the surviving leaders of the Russian Revolution confessed to one or more of setting up a terrorist organisation to kill Stalin, poisonings, sabotage, spying, planning to partition the Soviet Union between Germany, Britain and Japan, being fascists, being agents of Nazi Germany, and working to restore capitalism. How much more likely are false confessions amongst the inmates of Guantanamo Bay, Bagram or other military bases, whether guilty or innocent?

The polygraph or “lie detector”

This is a device which measures heart rate/blood pressure, breathing and skin conductivity (related to sweating). The theory is that when telling a lie these parameters are affected differently from when being truthful. As the American Psychological Association* points out, there are several problems with polygraph tests. Firstly, there is no evidence for the theory that there is a unique physiological response to deception. Secondly, there is a strong placebo response in those who believe that they work (and are therefore fearful). Thirdly, people (such as genuine spies) can be trained to outwit polygraph operators.

The evidence is that polygraphs are better than guessing (in the range 80-90%) but that there are a substantial proportion of false positives and false negatives. For instance, if there are 100 spies in the CIA, out of say 20,000 personnel, then perhaps 85 will fail a polygraph test and 15 won’t. But so will 2985 non-spies, so there will be over 3000 people to investigate. Worse, some of the spies will be able to evade detection through training. The polygraph is really worse than useless!