- Education and Science»
Confirmation bias, confirmatory bias, statistics, perception,
It seems that ordinary folk are doomed to misinterpret information and evidence. Without specialist training and strict control only dumb luck seems to prevail when making decisions about evidence.
What has a violin, a glass of water and a sonic insect repellent have in common?
People cannot tell the difference between a good modern violin and a Stradivarius.
The glass of water
A pure glass of water is identical to a homeopathic remedy.
Sonic insect repellent
Shouting at the mosquitoes is just as effective as a sonic insect repellent device.
A Stradivarius can cost millions of dollars and command a full-time body-guard. Yet a study in 2011/12 showed using blind experimental techniques that there is generally no perceptible difference in sound quality between one of these old instruments and a quality modern instrument.
The glass of water.
Homoeopathic remedies are diluted in water beyond any conceivable ability to detect a single molecule of the original additive. A substance is mixed with pure water, then diluted, shaken, diluted again, shaken and so on many times until the original substance in the water is essentially zero. Therefore, there is no difference between a glass of water and a homoeopathic remedy.
Sonic insect repellent
These devices simply don't work. Every scientific study performed using them as test objects show no statistically significant advantage as an insect repellent. Once particular manufacture claims the device mimics the ultrasonic chirp of a bat and therefore scares away mosquitoes. However, the mosquitoes are not sophisticated enough to make the connection and this is why controlled studies show they don't work.
Yet people say otherwise. Why?
I seriously doubt that anyone who has spent $2,000,000 on a violin will even glance in the direction of a scientific study claiming they were overcharged by a factor of 10,000. You might find musicians who would roll on the floor in agony upon hearing a sub-standard G note from a modern instrument.
Homoeopathic patients will swear they feel better after treatment with nothing more than pure water. Practitioners honestly believe they have a real effect. Yet there is not only no scientific reason to suggest there could be any effect at all, blind studies show it to be no different to the well known (and real) placebo effect.
People who have bought sonic insect repellent devices will often claim they work, perhaps because they are used in conjunction with other techniques like being cleaner in the house or using chemical barriers; or perhaps because they don't want to be seen to have wasted money.
Whatever the reason, it seems there is a very strong and almost unavoidable psychological twist to human reasoning that inevitably causes the brain and evidence to logically clash.
In the case of homoeopathic activity, a respected scientist called Jacques Beneviste published a paper in the prestigious journal Nature which claimed that water had some kind if imprint left from an initial dissolved substance, long after it was diluted away to nothing. To cut a long and interesting story short, his career was terminated after independent auditing showed that his counting procedure was exposed to human counting bias. The researchers peering into microscopes were aware of the sample origin, and which was the control. Despite their best efforts, they were humanly incapable of avoiding a counting bias. The bias in fact was the only statistical effect to be seen. When the experiments were repeated blind, the statistical significance vanished, and with it, Jacques' career and the memory of water.
Jacques Beneviste is not the only victim. Pons and Fleishman's Cold Fusion seems to fall into a similar category, and there is a famous historical case again originating in France known as N-rays.
The N-rays case is particularly interesting. René Prosper Blondlot (1849-1930) claimed to have discovered a new form of radiation. He followed the discovery of X-rays, and named his discovery N-rays because he lived in the town of Nancy, with a university of the same name.
These so called N-rays were confirmed by dozens of other scientists but each one was deluded by their own unconscious bias. They saw what they wanted to see. The experiment relied on a prism inside a metal tube, and the effect was apparently seen external to this tube. The flaw was revealed when an auditor secretly removed the prism and scientists still claimed to see the effect. When the scientists subsequently thought the prism was removed, but it was actually in place, the effect magically vanished. In other words, this was a hallucination caused entirely within the brain of the researchers.
I'd like to collect more examples. If you know of them please comment.
Here are some candidates:
- Sickness from electrical overhead wires
- Benefits of magnets in the bedsheets
- The difference between Coke and Pepsi
- Beer judging
- Wine tasting
- Bargain shopping
- Speaker cables
- Digital HDMI cables
- Pseudo Science
- Having rolled a few sixes on a fair die, what comes next?
- Choice of breakfast cereal
- Whiter-than-white clothes washing
- Political voting
- Investor portfolios
- The role of colour in advertising
- Trademarks that are too similar but come from different companies
- Large pills work better than small pills, and coloured pills work better than white ones.
- Clothing worn by accused during a trial
- Owners of particular computer operating systems
Confirmation bias is when you first take a position and then only accept evidence that supports it. It seems easy to identify and therefore easy to avoid, but in practice, even skilled researchers fall into the trap, and everyday, billions of decisions are made by ordinary people that are biased. We can't help it.
Hopefully, having seen some examples, and how powerful is this bias, it will help you read critically, make better decisions, and provide a useful tool for life.
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