If meetings really lower IQ…

… then there’s little hope for the world, says Alison Campbell, who attends far too many meetings. Fortunately however, that may not be the case.

I attend a lot of meetings; that’s the nature of my job. Recently the Dean came in and waved the front section of the NZ Herald under my nose. “Look,” he said, “all those meetings are really bad for you.” Scenting a way of getting out of them, I grabbed the paper and found the article in question (syndicated from the UK paper, The Telegraph).

“Attending meetings lowers your IQ,” cried the headline, and the article goes on to say that:

“[the] performance of people in IQ tests after meetings is significantly lower than if they are left on their own, with women more likely to perform worse than men.”

The story is based on a press release about research carried out at Virginia Tech’s Carilion Institute. And this showed that the research outcomes were more nuanced and more complex than the newspaper story would have it. The research found that small-group dynamics – such as jury deliberations, collective bargaining sessions, and cocktail parties – can alter the expression of IQ in some susceptible people (Kishida et al. 2012).

In other words, meetings don’t necessarily lower your baseline IQ. What they may do is change how you express that IQ, particularly if you’re susceptible to peer pressure. The internal urge to conform can result in people making decisions as part of a group that they might not have made on their own, especially if they have concerns about their status in that group. (As the Virginia Tech release notes, this was shown to good effect in the superb film 12 Angry Men, with Henry Fonda leading a stellar cast.)

The researchers placed study participants in groups of five and studied their brain activity (using MRI scans) while the groups were engaged in various tasks. While the groups were working they were also given information about the intellectual status of group members, based on their relative performance on those cognitive tasks. (There’s a tendency for people to place great store on relative measures of IQ, and where they personally sit on the scale.) And afterwards, when participants were divided on the basis of their performance into high- and low-performing groups before their IQs were measured again, they were found to differ quite signficantly despite the fact that all participants had statistically similar baseline IQs when tested at the beginning of the study.

“Our results suggest that individuals express diminished cognitive capacity in small groups, an effect that is exacerbated by perceived lower status within the group and correlated with specific neurobehavioural responses. The impact these reactions have on intergroup divisions and conflict resolution requires further investigation, but suggests that low-status groups may develop diminished capacity to mitigate conflict using non-violent means.”

As I said, this is altogether more nuanced, more complex, and much more interesting than the news story that caught the boss’s eye. I suspect I’ll be attending meetings for a while yet.

K.T.Kishida, D.Yang, K.Hunter Quartz, S.R.Quartz and R.Montague (2012) Phil.Trans.R.Soc.B 367(1589): 704-716.

The fallibility of eyewitness memory

Eyewitness testimony is commonly regarded as very high quality evidence. But recent research has shown there are many ways memories of events can become contaminated. This article is based on a presentation to the NZ Skeptics conference in Wellington, 27 September 2009.

In 2003, a woman was tragically attacked and raped after leaving a bar in Christchurch. She remembered her assailant as a man with “rat- like” features. Later, she chose the police suspect from a photographic lineup, indicating that she was “90 percent sure” that he was her assailant. This identification became the central piece of evidence that convicted Aaron Farmer. But, in June 2007, Mr Farmer was exonerated after DNA proved that he could not have been the rapist – he had spent almost three years in prison.

Unfortunately, Mr Farmer’s case is not an isolated incident. Decades of legal and psychological research have shown that eyewitness identification error is the leading cause of wrongful conviction. Recently the former High Court judge, Sir Thomas Thorp, published an extensive review of legal research on miscarriages of justice. In that paper, he estimated that there are at least 20 innocent people in New Zealand prisons, and he emphasised eyewitness error as a leading cause of convictions. This conclusion fits neatly with exoneration data from the Innocence Project, based in New York. Since 1992, the Innocence Project has exonerated over 250 wrongfully convicted people, over 75 percent of whom were identified by at least one eyewitness.

How can human memory be so fragile as to lead a witness to choose an innocent person from a lineup? Over 30 years of research has shed light on this question. Ultimately, this research has shown that memory can go wrong in several ways. The best way to understand these errors is to think of memory as a three-stage process:
[1] encoding,
[2] retention, and
[3] recall.

At the encoding stage, information is perceived and transferred from the environment, through our senses. These perceptual processes allow us to lay down memory traces. Next, those traces are retained for a period of time. Of course this retention stage can last for anywhere between seconds and years, until finally we recall that information from memory. It is important to know that any one of these three stages can go awry.

Encoding

Encoding depends heavily on our ability to pay attention to information in the environment. However, our attentional systems are limited. We can only pay attention to a few things at once. Anything that does not receive the requisite amount of attention does not have the chance to make it through the encoding phase of memory.

Furthermore, many variables, such as stress, can limit our attentional processes even more. As a result, witnesses will often not pay attention to details that could be forensically relevant. For example, a witness under stress may pay particular attention to the weapon being brandished by the offender, rather than paying attention to his facial details. If this is the case, those facial details may never be stored in memory, and if information is not stored, it cannot be recalled later.

Retention

The information that makes it into memory can be distorted easily. Perhaps the best known psychological science research in this field is the misinformation effect pioneered by Elizabeth Loftus. This research shows that a simple suggestion can change witnesses’ memories. In a typical misinformation experiment, there are three stages.

First, participants watch a simulated crime, such as a man stealing a maths book from a bookstore. After a delay, participants are exposed to post- event information (PEI), which is usually a narrative describing the simulated crime. For some participants, the PEI is accurate but generic (eg, “the man stole a book”), and for others the details are misleading (eg, “the man stole a science book”).

Finally, participants are questioned to determine their memory’s accuracy for the event. These participants are often specifically told to ignore everything they read in the narrative and only rely on what they saw during the event. Typically, those participants who read misleading details during the PEI have less accurate memories than those who read generic information.

This research shows the ease with which a person’s memory can be changed. Decades of research have shown that people can come to remember having seen a crime when in fact they have seen an innocuous event. Using this paradigm people can even come to remember having seen an innocuous event, when in fact they have seen a crime. Witnesses can often be exposed to misleading details from co- witnesses, suggestive interviewing techniques or sometimes, media reports of the crime. Any of these sources can lead witnesses to remember details that did not happen.

Recall

Psychological science has also shown that the way we test witnesses can also affect their memories for what they have seen. Some of the most prolific research in this field has examined the way that we test witnesses’ memories for offenders’ faces using the lineup technique. Photographic lineups are the most common method of testing eyewitness recall for offenders.

Usually, a lineup depicts a police suspect surrounded by known innocent people – known as distracters. A witness chooses a person from a lineup in the same way that a person chooses an option from multiple- choice question. When people choose the correct answer from a multiple- choice question it is considered evidence that they recognised the correct answer by relying on memory; and when witnesses choose the suspect from a montage, it is considered evidence that they recognised the suspect from the crime scene.

However, people do not always rely on their memory in either multiple- choice questions or lineups. A multiple-choice question can be biased towards the correct answer, as in this example:

What is the capital of Burundi?

Most people cannot rely solely on their memory to answer this question. Now consider these choices:

(a) Paris;
(b) Sydney;
(c) Wellington;
(d) Bujumbura.

You probably chose the correct answer (d), not because you had a memory for Burundi’s capital, but because you used a process of elimination to choose that answer. Similarly, a lineup is sometimes constructed so that witnesses do not need to rely on their memory for the offender; instead, they use a process of elimination – the suspect becomes the Bujumbura of the lineup.

Lineup bias

The danger arises when the wrong person is suspected of a crime and then included in a biased lineup. Research shows that witnesses will often choose from a lineup, even when the actual offender is not present. If the lineup has been constructed in a biased way (like the multiple choice question above), witnesses are even more likely to choose from the lineup. It is misidentifications like these that often lead to wrongful convictions.

Taken together, this research shows that witnesses’ memories are susceptible to several sources of error. As such, we need to ensure that we collect and test witnesses’ memories with scientifically valid interview and lineup techniques. Scientific recommendations regarding best practice procedures for witness evidence have been available for several decades, but few jurisdictions worldwide have taken them up. This lack of recognition for scientific validation is surprising given the relatively fast uptake of forensic science methods, such as DNA testing.

As a result, the best way to think of witness memory evidence is like biological evidence at a crime scene. If we were unlucky enough to stumble across a bloody crime scene, most people would be careful not to contaminate the scene by trampling through the blood spatter patterns, or handling any evidence. Similarly, we should treat witness memory with the same caution. When a witness has been exposed to a crime, we should not contaminate their memories with suggestive questioning and biased lineups. Instead, we should collect and preserve their memories with scenically valid techniques. Only then can we hope to reduce the increasing number of wrongful convictions caused by erroneous witness evidence.

Drawing Out False Memories

One possible source of the outlandish reports given by children in cases such as the Christchurch Civic Creche affair was described at the 2003 Skeptics’ Conference.

In recent years the western media has become increasingly cluttered with stories of bizarre goings-on with groups of children. Although nearly 15 years of scientific research has shown us that children can come to report a variety of false experiences, until recently we knew very little about how the more implausible and outlandish reports — of naked Japanese men playing guitars, of secret tunnels and hanging cages — might emerge.

This year, Rachel Sutherland, Maryanne Garry and Deryn Strange published the results of a scientific study designed to investigate whether a seemingly innocuous technique might be promoting these bizarre stories. The purpose of our research was to examine the role of imagination in the “Draw and Tell” interview to try and provide an explanation for how children can come to believe that impossible events have happened to them. We wanted to know if children could come to believe that they had participated in an impossible event just by drawing and imagining that they had. We asked children to answer a list of events on a Life Events Inventory (LEI). The list included typical childhood events as well as unlikely but highly imaginable events (the target events) such as, “have you ever flown to the moon on a rocket”. Children only had to say “yes” or “no”. One week later a novel experimenter asked children in the Draw group to draw what it would be like if three of the target events had actually happened to them. One hour after the drawing phase, the original experimenter returned and told the children that their original answers had been lost and asked if they would mind answering the questions in the LEI again.

We found that children in the Draw group were more likely to say that an event had happened. Put another way, the group exposed to the drawing task were much more likely to change their responses from “no” to “yes” when asked a second time whether the events had actually happened to them. In fact, the effect of drawing was not limited to the target events that children drew. Draw children were more likely to change their answers on all events, not just the ones that they spent time drawing.

The results of this experiment show that drawing might promote reports of events that did not occur. If children are given false event information in the context of an interview and then draw that information, that drawing may then make them more likely to claim that the suggested event has happened. In light of this finding, those in both legal and therapeutic settings should maintain vigilance when asking children to take crayons in hand or run the risk that further false memories will be “drawn out.”

Psychologists Not Suited to Court Work

Should we trust psychologists and psychiatrists, especially as expert witnesses in court cases?

This is an important question because, depending on their opinions, a person can inherit vast sums of money, lose custody of a child, be tried for murder or shut away for life in gaol or an asylum.

Two American psychologists, Jay Ziskin and David Faust, have looked at the performance of their own profession with a scientific eye and think they have good reason to question the accuracy of their colleagues’ opinions in courts. They point to several famous experiments.

In one study, several psychologists examined the same group of mental patients. The experts disagreed on the patients’ diagnoses, motivations or conflicts, and their conscious and unconscious feelings more often than they agreed on these things.

In other experiments, professional psychologists did no better than office secretaries in recognizing people with damaged brains, and few clinicians could distinguish between people with real brain damage and those only pretending. More studies showed that children feigning brain damage fooled most practitioners and professional psychologists did no better than high school students in predicting violent behaviour.

Several studies showed that psychiatric judgment did not improve with wide experience or special qualifications. Highly qualified old psychiatrists were no better than novices in spotting the presence, location or cause of brain damage.

Drs Faust and Ziskin think that many of these experts are ill fitted to work on criminal courts for two reasons. In their day-to-day work, psychologists and psychiatrists have an ingrained tendency to help and sympathise with their patients. But in the unfamiliar arena of the court they must do something quite different — uncover truth whatever the implications are for the accused, so their judgment is often clouded.

Another reason for their failure is because their disciplines are not yet true sciences. Human thought and behaviour still resist objective, direct, reliable observation and measurement, so clinicians can make few accurate predictions. In the place of science, psychology has only loosely bound conjectures — dozens of fash-ionable personality theories and hundreds of ever-changing approaches to psychotherapy. New theory may not be better, only a fresh attempt to resolve a recalcitrant problem.

Check this out in Jay Ziskin and David Faust’s three-volume Coping with Psychiatric and Psychological Testimony. Fifth Edition 1997. Nothing here about New Zealand psychologists and psychiatrists who are, of course, a cut or two above their American counterparts.

Originally published in the Dominion Post, January 26, 2003. A book of Bob Brockie’s collected columns is being released August 2003.

Newsfront

Death was “the Biggest Gift”

A Feng Shui practitioner who died while on a life mastery course in Fiji was ready to leave his body, his widow believes. Stephanie Challis, pictured in the Nelson Mail (11 December 2002) smiling happily with her three children, told how her 41 year old husband Will had undergone a course of body cleansing which involved colonic hydrotherapy and drinking quantities of good quality water.

“He always played full out,” she said. “My guess is that he had seven or eight litres of water, thinking, ‘the more I drink, the cleaner I am’.” Mr Challis mentioned that he had been throwing up, but Mrs Challis, having previously done that when detoxifying, didn’t think too much of it. She said his sodium levels had become unbalanced, leading to loss of consciousness. Because they were on an island facilities were not available to rectify his sodium balance, and he was not given any oxygen.

“It appears his brain suffered massive oxygen starvation in that first 24 hours. The doctors tell me they will never know.”

Mrs Challis said she met her husband through training in Qi Gong, an ancient form of energy cultivation, and the basis of their relationship had always been spiritual. In the months leading up to his death, they had been “full out” on various courses. She believes he was on an unconscious level preparing to leave his body. “There are so many amazing coincidences. It all points to the fact that this was his time.”

Mrs Challis said she had remained positive throughout the ordeal, and did not blame anyone for what happened and, in fact, feels privileged that her husband shared the experience with her. “I was keeping the bigger picture in mind the whole time. When he died I felt incredibly peaceful and even joyful. I realise since that what he’s done has been the biggest gift he’s ever given me. I feel closer to him now than I’ve ever felt and deeply grateful for what he has taught me about life through his dying.”

Out-of-Body Experiences at the Flick of a Switch

Doctors say that out-of-body experiences (OBEs) may be triggered by stimulation in one part of the brain (Dominion, 23 September 2002). Writing in Nature, the Swiss researchers say they were able to trigger OBEs in a female patient. They say their work may explain the phenomenon of people reporting having “left” their body and watched it from above. The doctors were studying epilepsy by using electrodes to stimulate the woman’s brain. They found that stimulating the angular gyrus in the right cortex repeatedly caused OBEs. At first, the stimulations caused the woman to feel she was sinking into the bed, or falling from a height. When the strength of the current was increased, she reported feeling she had left her body. The doctors believe the angular gyrus matches up visual information and the representation of the body formed by the brain’s touch and balance faculties. When the two become dissociated, an OBE may result.

Mormon Researcher gets the Wrong Answer

Anthropologist Thomas Murphy faces expulsion from the Mormon Church after showing by DNA analysis that native Americans are not descended from ancient Israelites, as the church claims (Dominion Post, 9 December).

The Book of Mormon, made public by Joseph Smith in 1830, is a cornerstone of church doctrine and taken literally by the faithful. It teaches, among other things, that America was populated by Israelites who went to North America 600 years before Christ – a time within the reach of archaeology and genetics. Mr Murphy, of the anthropology department at Edmonds Community College in Lynnwood, Washington, set out to test this, and his negative findings saw him charged with apostasy. It appears this is the first time a member of the Mormon Church has faced expulsion for genetic research.

Church leaders declined to comment on specifics of the case, but critics said they feared his excommunication would have a chilling effect on Mormon scholars who wanted to stay in the church.

Clone Petition Dismissed

The Raelians, of course, know full well that native Americans are not descended from Israelites. According to the cult they, and everyone else, owe their origin to extraterrestrials, who cloned themselves to produce the human race some 25 000 years ago. They’ve gained themselves a lot of publicity in the last few months with their claims to have produced human clones of their own (eg Dominion Post, 30 December). More recently (Reuters, 29 January) a Florida judge has dismissed a petition to appoint a state guardian for “Eve”, the first of three allegedly cloned babies, reportedly born on December 26. Clonaid, the company which claims to have produced the clones, says the baby is in Israel.

Expressing skepticism that a cloned child even existed, but expressing concern for its welfare if it did, Juvenile Court Judge John Frusciante said his court had no jurisdiction in the case. Clonaid president Brigitte Boisselier testified that the baby had never been anywhere near the United States.

Clonaid has produced no evidence for any of the clones. Scientists widely believe the assertions are a hoax to make money or garner publicity for the Raelians.

Boisselier, a French-born chemist who is a member of the Raelians, would not say where in Israel the child was, adding she did not know as she was no longer in contact with the parents. She also told the court that she had not seen the baby, although she had seen videotapes.

Bernard Siegel, a private citizen and attorney, filed the petition earlier this month asking for the state to appoint a guardian to supervise her care. He said that if “Eve” were indeed a cloned child she could face serious medical problems.

In dismissing the case, Frusciante made plain his concerns about cloning, citing at one point President Bush’s remarks during his State of the Union address on Tuesday in which Bush said no human should be started or ended as the object of an experiment and asked Congress to ban cloning.

Clonaid, which made the initial announcement of “Eve’s” birth at a hotel in Hollywood, Florida, backed away from its earlier promise to provide DNA proof of the cloning after Siegel filed his petition. The company, which does not reveal where it is located or anything about its finances, now says that it has deliberately cut links with “Eve’s” parents to ensure their privacy.

The lawyers representing Clonaid had urged Frusciante to dismiss the petition. “The case was a preposterous case, there was no basis for it,” attorney Jonathan Schwartz said after Wednesday’s hearing.

But Siegel said he was glad he presented the petition even though it failed, not least because it had prompted Boisselier’s testimony under oath that a cloned child existed and was in Israel. He added he hoped the Florida Department of Children and Families, which had representatives in court on Wednesday, would alert the relevant authorities in Israel to the possibility of a child in need of protection.

And now it’s Homeopathic Vets

The first output from a new diploma course in homeopathy graduated at the end of last year (Rural News, December 2). The four women are mostly veterinarians who have taken the course at the Bay of Plenty College Auckland Campus. New Zealand Homeopathic Council president Joan Goddard says the qualification is unique, and is the first time that basic medical knowledge has been taught beside homeopathic treatment and diagnosis in an animal health course.

Students take a part-time one-year foundation course before electing to complete the two or three-year diploma.

Goddard says most of the students graduating this year are veterinarians looking to extend their treatment capabilities.

“Vets treat the diploma as an additional skill to use on herds and do not rely solely on homeopathics.”

She hopes the course will set up a list of standard homeopathic treatments for various animal conditions, as many current practitioners depend on personal experiences to treat animals. Twelve students should graduate in 2004, with similar numbers going through the course.

Goddard hopes course numbers will gradually grow but says there are only a limited number of people to teach students. Well that’s something, I suppose.

Spookiness is in the brain of the beholder

Whether or not you believe in the paranormal may depend entirely on your brain chemistry. People with high levels of dopamine are more likely to find significance in coincidences, and pick out meaning and patterns where there are none.

Peter Brugger, a neurologist from the University Hospital in Zurich, Switzerland, has suggested before that people who believe in the paranormal often seem to be more willing to see patterns or relationships between events where sceptics perceive nothing.

Brugger persuaded 20 self-confessed believers and 20 sceptics to take part in an experiment in which they were asked to distinguish real faces from scrambled faces as the images were flashed up briefly on a screen. The volunteers were then asked to idenify real words from made-up ones. Believers were much more likely than sceptics to see a word or face when there wasn’t one, Brugger revealed. However, sceptics were more likely to miss real faces and words when they appeared on the screen. The researchers then gave the volunteers a drug called L-dopa, which is usually used to relieve the symptoms of Parkinson’s disease by increasing levels of dopamine in the brain. Both groups made more mistakes under the influence of the drug, but the sceptics became more likely to interpret scrambled words or faces as the real thing. That suggests that paranormal thoughts are associated with high levels of dopamine in the brain, and the L-dopa makes sceptics less sceptical. “Dopamine seems to help people see patterns,” says Brugger.

However, the single dose of the drug didn’t seem to increase the tendency of believers to see coincidences or relationships between the words and images. That could mean that there is a plateau effect for them, with more dopamine having relatively little effect above a certain threshold, says Peter Krummenacher, one of Brugger’s colleagues.

Dopamine is an important chemical involved in the brain’s reward and motivation system, and in addiction. Its role in the reward system may be to help us decide whether information is relevant or irrelevant.

New Scientist July 27 2002

Rats, Scientists and Experimental Design

John Riddell learns about some dangerous chemicals

From the TV3 News website:

CHIPS COULD CAUSE CANCER UPDATED: 05:56PM WEDNESDAY 26 JUNE

The World Health Organisation has begun a three-day emergency meeting in Geneva to evaluate the danger of some popular foods. They’re concerned about a recent discovery that certain starchy foods, from deep fried chips to potato chips and bread, contain a chemical called acrylamide. It can cause cancer in rats, but there is no evidence it does the same in people.

There are lots of chemicals in food. Even organic food. Are the chemicals in our food dangerous? Is food safe?

For example many foods contain a chemical called cellulose. How much do we really know about cellulose?

If I want to know if cellulose is dangerous I need to design an experiment. Experimental design can be tricky.

I have limited resources. The best thing to do would be to look at a large sample of individuals. See what happens when they are exposed to small amounts of cellulose over a long period of time. Unfortunately I don’t have the resources to study this way. So I choose to use a high dose of cellulose over a short time period.

I get a rat and put it in a cage. I place the cage about five metres from the base of a 25 metre tall tree. Using a chainsaw, I chop down the tree so that it falls on to the cage containing the rat.

Then I have to repeat the experiment a few times to make sure the first result wasn’t a fluke.

Every single time I have carried out this experiment the rat has died. The conclusion is obvious. Cellulose is dangerous.

Next I must publish the results of this experiment in a “peer reviewed journal”.

This is in the unlikely event I have made a mistake somewhere. If there is something wrong with my experiment, hopefully someone will spot it.

Somebody did. They raised the point that it might not have been the cellulose that killed the rat. Trees also contain other chemicals such as lignin or even water. Maybe it was one of the other chemicals?

Good point. I have to consider the criticism and design a new experiment to answer this question.

Since a tree is mostly water I design another experiment to test if it could have been the water that killed the rat. I put a new rat, in a cage, into 100 litres of water.

And the rat dies.

So I conclude that water is harmful to rats. But this does not necessarily mean that cellulose is not also harmful.

After all, I noticed that while the tree killed the rat instantly, the water took a few minutes. Perhaps there was something in the combination of cellulose and water that made the tree more harmful than merely water alone.

But before I look at the synergistic effects I want to extrapolate these data to look at how dangerous small doses of water might be.

If 100 litres of water causes death in three minutes this suggests 50 litres would cause death in six minutes. Continuing this extrapolation shows that even a small amount of water will significantly reduce the rat’s life expectancy.

Also, what are the implications for humans?

Anecdotal evidence suggests that many humans who have been in large amounts of water have also died. As yet I haven’t yet been able to obtain funding to test this myself. However if water really is dangerous, can we risk even the smallest exposure?

Okay, some scientists have raised doubts about the validity of high dose trials. Just because a high dose of a chemical is harmful, they say this doesn’t necessarily mean that smaller doses are also harmful. And just because it is harmful to rats doesn’t necessarily mean it is harmful to humans.

But can we afford to take the risk? Do we really know the dangers? The results so far are inconclusive. Obviously more research is needed. I just need a bit more funding. However there is one conclusion we can draw.
Scientists don’t like rats, but I suspect the feeling is mutual.
No rats were harmed in the preparation of this article.

Medical Evidence

In the second of a two-part series, Jim Ring looks at what evidence means to different people

Scientific evidence is often difficult to interpret, in medicine in particular. ‘An Unfortunate Experiment’ was the title given to the treatment for some women after screening for cervical cancer. In this case science was considered by the legal profession and apparently found wanting. The doctor involved was castigated and publicly humiliated for experimenting on humans. But no real experiments were ever done; it appeared he did not understand scientific methodology. Neither did the journalists and legal people involved. The point is that no proper controls were used so it was very poor science.

Were the women disadvantaged? It is difficult to tell, but many were certainly outraged. It generally escaped notice that the surgeon was responding to public pressure for less radical surgery and that a group of patients involved seem to have had on average a slightly better outcome than the norm.

One of the most unfortunate ideas that came out of the long legal case was the emphasis on privacy for the individuals involved which implied their records should not be available for medical study. There is a difference between privacy and anonymity. It is very important to explain to those involved in medical procedures that for medicine to progress it is essential to collect data. Women appeared on TV complaining bitterly that they had been used in an experiment without their consent. But all good medicine is experimental.

We are not much closer to determining whether mass screening for cervical cancer does improve the chances for the screened population and now we have another scandal in New Zealand. Public expectation of screening programs is far in excess of what they can deliver. Efforts to sue Dr Bottrill, and compensation claims from ACC, seem to imply that patients think a false negative reading is necessarily medical error. Women have appeared on TV claiming their lives have been devastated because they had a false negative. Surely this is wrong; they are rightly upset but this is because further tests show a medical problem. Of course some who died might have been saved if an early intervention had resulted from a correct positive reading; however this does not seem to be the main thrust of their complaint.

False Negatives vs False Positives

It is possible to reduce the number of false negative readings at the expense of an increase in the number of false positives. This may seem desirable but there is a cost. In Britain large numbers of women in a screening project reacted very badly to finding they might have a ‘pre-malignant’ condition. This included some members of the medical profession. There is a clear indication that patients were not well informed before screening.

Patients involved in any medical procedure are supposedly asked for their ‘informed consent’. It seems now obvious that ‘informed consent’ is largely lacking during mass screening for both cervical and breast cancer. Several of those involved in the public hearing are surprised to find that screening is less than 100 per cent accurate. All mass screening procedures are likely to have a high error rate as they are designed to be rapid, cheap and simple; leading to more precise testing if there is a positive result. Is a large and expensive inquiry, using legal methods, a suitable way of investigating scientific questions?

Cervical cancer, unlike breast cancer, is strongly correlated with environmental factors. The former is very rare in the general population with a relatively high incidence in a certain sector. However it is politically incorrect to target the high-risk population for screening because the risk correlation is with such factors as poverty, poor hygiene and sexual promiscuity.

A recent case of a gynaecologist accused of misconduct raises some interesting issues. The unfortunate patient would seem to be outside the high-risk group for cervical cancer, thus an assumption may have been made that the correct diagnosis was very unlikely. But no physical vaginal examination was made. Feminist literature once strongly criticised the medical profession for over-use of this procedure, which one writer described as ‘legalised rape’. It would be interesting to know the rate at which this procedure is used today compared with, say, 30 years ago. Is the medical profession responding to crusades in a way that disadvantages patients?

Objections to trials

Medical ethicists – now a profession – have objected to various drug trials saying it is unethical to provide some patients with a placebo that will not improve their condition. This is in effect a claim to certain knowledge – that the drug being trialed is the ideal treatment. Patients receiving a placebo are not disadvantaged when the new drug may do more harm than good. We can sympathise with terminally ill patients who know that they will die in the absence of treatment and where anything seems a better bet than a placebo. But it is essential that drugs be properly tested before being used routinely.

Experiments have even been done in surgery. In 1959 patients were randomly assigned, but all prepared for surgery and the chest cavity opened. Only then did the surgeon open an envelope and follow the instruction; either to perform the procedure or immediately close the chest. Although some ethicists have objected (one stated that such surgery would never take place in the UK), a double-blind study of brain surgery was recently done in the US. Not only did it pass an ethics committee but patients welcomed the chance to take part even though it involved drilling the skulls of both real and placebo patients. In this case there was considerable improvement in those under 60 who had the real operation.

This indicates people may be willing to give consent to risky experiments providing they are given good information.

Most evidence in medicine comes not from experiments but from epidemiology. This requires the collection of huge amounts of data and sometimes produces conflicting results. Two populations, which differ only in the factor under investigation, should be matched and this is difficult to achieve. Recently, in a world-wide study, doubt has been cast on the efficacy of breast-cancer screening. New analysis purports to show that when populations are matched correctly, the screened population has no better chance of survival than an unscreened population.

Demands for safety

Some demand that all medical procedures should be ‘safe’, though curiously this is not required of alternative medicine. Suppose a new drug has fatal consequences for one patient in 100,000. It is quite likely that this will not be discovered during testing. Should such a tiny risk preclude the use of a drug that gives significant benefits to the vast majority of patients? New medicines are introduced when they show a clear advantage over a placebo. When very large numbers are involved in a study it is possible for a drug to show a significant advantage, yet not be worth introducing. Significance is a technical term and it is possible to find an advantage of only 0.1% is ‘significant’, though it may not be worth taking such a product.

It was this confusion that bedevilled early experiments on ESP. Rhine in America and Soal in England recorded the success of subjects guessing unseen cards. The experimenters wrongly assumed controls were unnecessary; instead they compared guesses with a theoretical chance result. A few subjects scored correct guesses at slightly more than chance and because huge numbers of guesses were involved, statistical tests showed these results had ‘significance’. That is, there was a huge probability that the guesses were not simply ‘lucky’.

Enthusiasts then made the enormous leap to say that because the guesses were not due to chance they must be due to a previously undiscovered human faculty, extra-sensory perception or ESP. Disinterested observers, not just skeptics, should have concluded that other explanations, such as poor experimental design, badly recorded results, fatigue, or just plain cheating were more likely. A great deal of time, money and effort was spent pursuing this will-o’-the-wisp.