Bias clue in explaining false belief

IT IS COMMON for people to pay attention to evidence that supports what they want to believe and to ignore evidence to the contrary. This phenomenon is called confirmation bias, a term coined in 1960 by British psychologist Peter Wason. Confirmation bias goes a long way towards explaining, for example, why sects that confidently announce the date of the end of the world, remain unfazed when the prediction fails to come true.

The latest such prediction came from Harold Camping, a preacher from California, who predicted the Second Coming of the Lord would happen at 6pm on May 21st, at which time about 2 per cent of the population of the world would be “raptured” to Heaven while 98 per cent would be sent to Hell.

Camping preaches through the Family Radio network in 48 languages and claims to have hundreds of thousands of followers worldwide. This is not the first time he incorrectly predicted the end of the world, having previously picked September 1994. But the really interesting thing is that the failed predictions do not cause significant defections among his following. The psychological explanation for this is confirmation bias.

Harold Camping’s followers are fundamentalist Christians who interpret the Bible literally. This interpretation provides a detailed explanation for everything – why the world exists, how everything was created why humans exist, our human purpose in life and how to attain eternal life. This is very satisfying – people who believe this explanation really want to believe and just know they are right. This predisposes them to seriously consider only such evidence from other sources that supports their worldview.

All Christians take the Bible seriously, but my problem with Camping is his simplistic literal interpretation, which also moves him to reject some major findings of modern science, eg biological evolution.

Fundamentalist religious groups are only one of many examples of the operation of the confirmation bias. This bias works very actively to shore up political ideologies, environmentalist world views, social and economic analysis, etc. For example, I once got a call from a Cork environmental group. The Radiological Protection Institute of Ireland had announced higher than average radon levels around Cork Harbour. The caller asked what harbour industries were responsible for these radon emissions. I explained that radon is a natural radioactive gas that emanates from rocks in the ground and had nothing to do with industry. At this point my caller lost interest. She would have been interested if the radon were emitted from a factory, but had no interest in natural radon. Of course, the health risk from radiation is the same whether its source is natural or industrial.

Why are religious sects not devastated when their end-of-the-world predictions fail to come true? Well, they seize on an explanation (evidence) that supports their basic beliefs. When Camping’s 1994 prediction didn’t come through, he explained that he had made a mistake in his calculations – he uses a complicated mathematical method.

Another current example of confirmation bias in action, in my opinion, relates to evaluation of the health effects of radiation released in the 1986 Chernobyl nuclear accident. These effects have been studied for 25 years by bodies with impeccable credentials, including the World Health Organisation (Who), United Nations Scientific Committee on the Effects of Atomic Radiation (Unscear), The Chernobyl Forum. These bodies have evaluated all the peer reviewed scientific research and have concluded that the ill-health effects attributable to Chernobyl are surprisingly small.

However, in 2009 the New York Academy of Sciences (NYAS) published a collection of research papers translated from Russian and other Slavic languages on the health effects of Chernobyl. These papers claim far greater ill health effects than those reported by Who, Unscear and The Chernobyl Forum.

Many/most of these Russian studies fall far short of accepted scientific standards (use of proper controls and rigorous statistical analysis, etc) and would not be accepted by mainline peer-reviewed scientific journals. The NYAS has distanced itself from this work. I am convinced by the mainline evidence published by Who, Unscear and the Chernobyl Forum, but, others, eg Greenpeace and the Chernobyl Childrens Project International, who have always claimed that Chernobyl caused major ill-health effects, enthusiastically quote the NYAS book to support their belief. To me, to be convinced by slapdash analyses whose conclusions fly in the face of rigorous mainline science, is an illustration of confirmation bias.

Prof William Reville is a member of staff of the Biochemistry Department UCC and the University Public Promotion of Science Officer – understandingscience.ucc.ie