Mass Belief and the False Consensus Effect
Everyone Believes It So It Must Be True!

#beliefs #epistemology #knowledge #popularism #science #sociology

Time and time again mass-delusions have swept the world. Their downfalls are often occasioned only slowly, as the evidence and careful checking, plus, having time to think, slowly results in a culture-wide change of opinion. The most common thing that perpetuates these errors is believing in them based on personal testimonies. For example, many people argue that particular religions must be true because of how many other people believe in them1,2. Linked to this is many who chose to believe something because of the age of the belief3. Furthering such poor logic is a lack of understanding of statistical likelihood, and ignorance of thinking errors such as selection bias (where we notice confirming evidence but ignore disconfirming evidence). Because we instinctively value the popularity of a belief, our minds play a further trick on us: we tend to over-estimate how popular our own opinions are - psychologists call it the false consensus effect4. The basis of belief should be in the weight of evidence and not in a popularity contest.

Fallacies do not cease to be fallacies because they become fashions.

G. K. Chesterton (1930)5


1. The Failure of Common Sense


Common Sense does not provide an indication of what is ultimately true. It was once "common sense" that atoms were indivisible, that the Earth was flat, that the sun orbits the Earth and that Gods get drunk and mate. But so many things are overturned by subsequently discovered evidence, that what is "common sense" must only ever be trusted as an instinctive guide to practical life, and not a guide to reality or truth. That "everyone believes it" is not a good reason to believe in something. All things must be made subject to rationality and methodical logic, otherwise, popular untruths will flourish. Many things that "everyone believes" turn out to be cultural, subjective and wrong.

It is not only in the physical sciences where the beliefs of the masses have turned out to be wrong. Mass morality and popular religious beliefs are both equally susceptible to change. It was once assumed that slavery and sexism - both defended and upheld by every historical world religion6 - were both natural and correct aspects of Human behaviour. Women and slaves were inferior and could not be trusted to be freed, nor did they have the intelligence to be independent. Now we know that such things are cultural, subjective and wrong. Now the opposite is obvious. Things that we think are obvious - things that "everyone believes", will almost always be overturned. Only modes of thinking that allow new evidence are wise.

The riotous tumult of the crowd is always very close to madness.

Alcuin (8th century CE)7

Time alone can wean men and nations from popular illusions which have been transmitted from generation to generation.

"The Supernatural?"
Lionel A. Weatherley (1891)8

2. Conformity

Social experiments by Sherif and then Asch provided much of the backbone for research into social group conformity. Members of a group who are asked to make judgements frequently conform to the group's average opinions: Even when the experiment is set up so that the group is clearly wrong! Peoples' instinct to conform in areas of opinion and judgements of facts can be very strong9. Research shows that the more public and open a persons' statements are, the more they will conform to social norms. Obviously this has ramifications for the concept of social mass belief, because social norms will override intellectual judgement even when individuals are presented with clear facts. However, the Adaption-level Theory of Blake and Helson correctly added the role of personality to the list of factors that affect social behaviour. Indeed, it was found that some people consistently conform negatively. That is, they go against social norms as a rule of thumb. They are under the control of the social group and behave predictably, just like most other people. Such people are therefore no more suitable for shedding cultural factors and arriving and objective, studied opinion.

The solution to this dilemma is education: When people study particular theories and the evidence for and against them, they can arrive at opinions which are then not controlled by subsequent social pressure. Ultimately, all opinions are under the influence of social cause-and-effect and eventually of the deterministic physical sciences that belie any free will. But, if academic study precedes public examination then opinions are more likely to be logical, rather than conformist.

Book CoverWhy is it that groups of highly intelligent people often make bad decisions? What do companies have in common when it comes to making good group decisions or bad decisions? In [chapter 5 of this book], we'll examine groupthink. We'll also explore the negative effect of communal reinforcement on critical thinking. Communal reinforcement is the process by which a claim becomes a strong belief through repeated assertion by members of a group or community. The process is independent of whether or not the claim has been properly researched or is supported by empirical data significant enough to warrant belief by reasonable people. [...]

Communal reinforcement explains how entire nations can believe in such things as witchcraft or demonic possession. It explains how testimonials reinforced by other testimonials within the community of therapists, sociologists, psychologists, theologians, politicians, talk show aficionados, and so on, can be more powerful than scientific studies or accurate gathering of data by unbiased parties. In addition, communal reinforcement can be used to build shields against those who might challenge the status quo. [...]

Groupthink plagues leaders who are not so great. Some of the traits of groupthink are: 1. Excessive optimism that encourages taking extreme risks; 2. Excessive confidence that excludes reconsidering assumptions; 3. Excessive demand for conformity that leads to self-censorship and to seeing critics as enemies. Great leaders, on the other hand, take risks that are based on rational and fair-minded assessments of all the relevant data. They encourage their people to express their feelings and beliefs, but require them to back up their claims with data. They are not afraid to examine their assumptions. They see critics as friends rather than as enemies. Critics force you to examine your decisions, your assumptions, and your values; they don't allow you to get away with sloppy thinking. Hence, they are a valuable asset.

"Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed!"
Robert Todd Carroll (2011)10

Some of the solutions offered by Carroll include having independent thinkers come to their own conclusions, and then consulting their results - by making a conscious decision to include such outside thought processes, you are much more likely to get a fuller and more accurate picture of the possibilities11.

In "Six Thinking Hats" by Prof E. Bono (1985) the author lays out a solution to the problem of group thinking: always have a black-hat thinker. This is someone whose job it is to find problems, nit-pick, think ahead, oppose the group, and present problems. Because it is their job to do this, they can't get caught along with the ideas of the group. The boss gives them the task of being contrarian. Once this is seen in action, all participants quickly learn the value of critical thinking in a constructive manner because it quickly becomes apparent that the "yes man" approach simply doesn't lean to good decision making.

3. Example Mass Failures12

3.1. Phrenology (1800s to 1950s)12


In the 19th century, the science of phrenology was ubiquitous in the so-called developed world. "Its influence was felt in anthropology, criminology, education, medicine, psychiatry, art, and literature. [...] In Australia, it rationalized the violence against Aborigines and explained the criminality of convicts. For ordinary people everywhere a head reading was often required for employment or marriage. But how could this happen if phrenology was totally invalid?"13

It was based on the idea that as the brain has specialist areas for certain behaviours. This correct fact was demonstrated from cases of brain damage where people lost certain skills or had certain aspects of their personality changed. Phrenology came about when it was theorized that you could measure the shape of a person's skull and therefore detect which parts of their brain were enlarged, and therefore active or dominant. You could therefore measure personality traits, both conscious and subconscious. A huge following produced masses of literature, documentations and manuals on this subject. Lots of people made lots of money from it, and, even more people from government officials to private psychologists, clamoured for the know-how of phrenology.13

But the entire escapade was a result of errors in thinking, and a complete lack of statistical overview to see if the method actually worked in a provable sense. It became an art more akin to the cold-reading that con-artists do to make acceptable statements about other people's lives. For example "cautiousness" was equated with there being a bump above the ears - because a highly cautious priest had a bump there. Practitioners and subjects then all agreed that if there was a bump there in cautious people it is because phrenology was correct; if there wasn't a bump, it was because some other aspect of personality was overriding it. In other words: people could find evidence for it easily, and discount evidence against it with ad-hoc theories. It was unscientific because it did not put forward testable theories. It was based on rhetoric, coincidence and subjective interpretation. The books of "evidence" for it were comprised of anecdotes and testimonials, not of science. But none of those shortcomings was apparent to an entire culture, an entire generation, of those who believed in it, including serious people from doctors and prison wardens, to psychiatrists and police investigators. Such is the power of confirmation-bias combined with cultural enthusiasm and mass belief.13

When much-needed testing was carried out, it was a disaster for phrenology. By doing things like taking ten head casts of famous individuals and carefully measuring each bump, and comparing results, it was easily demonstrated that there was no factual basis to the art. "But phrenology was slow to die. In the 1950s phrenologists still existed in Britain and in the larger American cities." It lasted so long despite a mountain of counter-evidence that it became "one of the most thoroughly discredited theories in the history of physiological psychology".13

3.2. The Earth is Flat, at the Center of the Universe, and the Sun Revolves Around it (3rd Century to present day)12

#christianity #greece

Sometimes, mass opinion becomes entrenched as the defined beliefs of dogmatic institutions. Such is what tends to happen with religion. As time goes on, even though the masses gradually move on from more ignorant beliefs, these institutions then fight tooth-and-claw to hang on to old beliefs. Sometimes, heroic scientists find themselves entrenched as individuals in battles against such powerful organisations a battle that they rarely win. However, despite this, evidence and facts, once revealed, have a tendency to slowly grow in support. The Christian idea that the Earth was the most special place in creation, combined with the common-sense experience that the world looks flat, meant that in the Christian west we languished for thousands of years under beliefs that the Greeks and Babylonians (amongst others) had already discovered to be false.

Scientists had to suffer torture, silencing, imprisonment and death at the hands of Christians who didn't agree with newly discovered facts about the world. Christianity lost the first battle with astronomers who realized that, contrary to what Christians asserted, the Sun did not orbit the Earth, and that the Universe doesn't seem to be designed specifically for humankind. Copernicus (1473-1543), Kepler (1571-1630), Galileo (1564-1642), Newton (1643-1727) and Laplace (1749-1827) all fought battles against the Church when they published scientific papers challenging religious orthodoxy. Bible verses were all the theories Christians needed; and Joshua 10:12-13, 2 Kings 20:11, Psalms 93:1, 104:5, Ecclesiastes 1:5, Isaiah 30:26, Isaiah 38:8, 1 Thessalonians 4:16-18 and Habakkuk 3:10-11 all contradicted astronomers. But through intelligence and clever politics, truth gradually won out over dogma, and the Church retreated... only to go on to fight similar ignorant battles, and violently impose dogmatic errors, in the arenas of physics, biology and philosophy.

Without such interference from theists, science would have been more than a thousand years more advanced! Kepler in the 17th century only revived Greek astronomical knowledge that was condemned and hidden by Christians (Ptolemy et al) in the second century.

There are still multiple Christian organisations that actively fight against heliocentric theory, spreading flyers and running websites stating that science has got it all wrong. See: Christianity v. Astronomy: The Earth Orbits the Sun!: 5.2. Christian Flat-Earth and Geocentric Societies.

3.3. Alternative Therapies and New Age14

#alternative_therapies #new_age #pseudoscience #self_development #USA

The New Age is full of an amazing variety of self-help ideas, 'cures' and therapies. Some consider the New Age to be nothing but a movement based on popular self-help practices. Most complementary and alternative medicines (CAM) and alternative therapies work through indirect psychological effects, and by the turn of 20th century many New Age related remedies and practices were already said by psychologists to be based on cures by suggestion15. The diversity of approaches, organisations, meetings and methods is outstanding, even if, unfortunately, the actual techniques are generally all complete quackery, and based on some very outlandish and nonsensical ideas of the human psyche. My page on Pseudoscience and Health: The World of Alternatives (to Truth) briefly introduces some of the more popular things found in all New Age shops. Explorations of Hopi ear-candlers, Shamballa Multi-Dimensional Healing, astral-plane projection healing, past live memory recursion, crystal healing, tarot card psychotherapy and other zany otherworldly services will have to be done by the intrigued reader in his own time!

  1. Acupuncture
  2. Astrological Readings and Horoscopes
  3. Colour Therapy
  4. Fad Diets
  5. Herbal Remedies
  6. Homeopathy
  7. Chiropractic: The Comparison Test
  8. Phrenology (1800s to 1950s)
  9. Quantum Physics, and Electric Trickery: How Modern Science is Turned into Pseudoscience

Many of these products are wider than just being "New Age" services, and are widely embraced, often to the worry of medical observers and sociologists. In the USA up to 4 in ten adults use 'some form' of alternative therapy16. In Britain there are about 150 000 alternative therapists, and the public spend about £4.5 billion on them (as of year 2009)17. In nearly all practices, they work due to the psychology surrounding 'treatment' (the placebo effect and statistical regression) rather than the actual result of the treatment. This is why drugs companies spend more on branding and advertising than they do on research and development18. Nearly all alternative therapies are psychological trickery rather than real medicine19. All such practices are called quackery by skeptics. The danger is that many people seek help from 'alternative' providers before they seek proper medical help, which can result in delayed treatment and in the worst cases, death from ailments that are otherwise perfectly curable if only the sufferer had gone to a normal doctor sooner16. "Some homeopathic remedies may contain substances that are not safe, or that interfere with the action of other medicines" and a real doctor should be consulted before using alternative therapies20 (including those that say they are 'natural' - so are many poisons).

3.4. Religion 21

#bahá'í_faith #causes_of_religion #christianity #mass_belief #popularism #religion #theism

No more is the mass belief fallacy perpetuated more widely than in the world of religion. Notice how the argument is used selectively - they ask how can two billion Christians be wrong? But there were times when Christianity was not the most popular religion; does that mean that the truth changes over time? A more general argument for theism is seen as "many believers point to the popularity of belief in gods itself as proof that gods are real"2 but what they don't realize is the true diversity of belief; it is safe to say that theistic Satanists don't believe in the same god as do theistic Bahá'ís, at all. Another, even more general, argument is that "religion is true" in general - "almost everyone in religious"22 but this isn't an argument for any particular belief; I suspect such an argument is not an argument best used in the defence of what is true but rather in the defence of being nice to people's beliefs, but with the side-effect of fostering delusion.

... believers point to the age of their religion as some sort of evidence for their god's existence. A lie or a mistake, they declare, could not have endured for so long. [...] Does the fact that some Greek citizens are still worshipping ancient gods in the twenty-first century prove that these gods are real? ... Hinduism is so old that it can take on anybody's religion in the age race.

"50 Reasons People Give for Believing in a God" by Guy Harrison (2008)3

What is important is the evidence for or against belief, rather than a count of how many people believe it. We are all so easily deluded, especially by things that are told by one person to another in a social context.

See a full page on What Causes Religion and Superstitions?

4. The Scientific Method

It is foolish to accept something just because everyone else believes it. But what are the grounds of reasonable knowledge?

All Human thought is subjective and fallible. Cultural norms and assumptions disrupt serious attempts to search for truth. The scientific method minimizes Human error. Any system of thought that proclaims itself to be "ultimate" or beyond correction is dogmatic and wrong: The best theories are the ones that happily give way to better theories. The worst are the ones that do not budge and refuse to admit new evidence that disputes them. They become stagnant and outdated. Science is revolutionary because it accepts new facts, new evidence and new thought. New knowledge acquired from the scientific method frequently changes society with technology and ideas. It is refreshing, challenging and above all the scientific method continues to dynamically improve its description of the world.

"What is Science and the Scientific Method?: 7. Conclusion" by Vexen Crabtree (2014)

5. Other Thinking Errors 21

By Vexen Crabtree 2006 May 31
(Last Modified: 2017 Jan 15)
Parent page: Science and Truth Versus Mass Confusion

References: (What's this?)

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The Economist. Published by The Economist Group, Ltd. A weekly newspaper in magazine format, famed for its accuracy, wide scope and intelligent content. See for some commentary on this source..

The Bible (NIV). The NIV is the best translation for accuracy whilst maintaining readability. Multiple authors, a compendium of multiple previously published books. I prefer to take quotes from the NIV but where I quote the Bible en masse I must quote from the KJV because it is not copyrighted, whilst the NIV is. Book Review.

Skeptical Inquirer. Magazine. Published by Committee for Skeptical Inquiry, NY, USA. Pro-science magazine published bimonthly.

Bono, Prof E.
(1985) Six Thinking Hats. Paperback book. 2000 edition based on revised First Back Bay 1999 edition. Published by Penguin Books Ltd, The Strand, London, UK.

Carroll, Robert Todd. (1945-2016). Taught philosophy at Sacramento City College from 1977 until retirement in 2007. Created The Skeptic's Dictionary in 1994.
(2011) Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed!. E-book. Amazon Kindle digital edition. Published by the James Randi Educational Foundation.

Goddard, Henry H. Dr
(1899) article "The Effects of Mind on Body as Evidenced by Faith Cures" published in The American Journal of Psychology (1899 Apr) vol. 10, No. 3, pp. 431-502. In James (1902) p112.

Goldacre, Ben. MD.
(2008) Bad Science. Published by Fourth Estate, an imprint of HarperCollins Publishers, London, UK.

Harrison, Guy P.
(2008) 50 Reasons People Give for Believing in a God. E-book. Amazon Kindle digital edition. Published by Prometheus Books, New York, USA.

McConnel, James V.
(1986) Understanding Human Behavior. Hardback book. 5th edition. Originally published 1974. Current version published by CBS College Publishing, Holt Rinehart and Winston, New York, USA.

Momen, Moojan
(1999) The Phenomenon Of Religion: A Thematic Approach. Paperback book. Published by Oneworld Publications, Oxford, UK. Book Review.

Myers, David
(1999) Social Psychology. Paperback book. 6th ('international') edition. Originally published 1983. Current version published by McGraw Hill.

Thomson, Oliver
(1993) A History of Sin. Hardback book. Published by Canongate Press.

Weatherley, Lionel A.
(1891) The Supernatural?. Hardback book. Published by J. W. Arrowsmith, Bristol, UK. This is a hard to find book. Bath Library has a copy, accessed 2012 Dec 14.

Wheatcroft, Andrew
(2004) Infidels: A History of the Conflict Between Christendom and Islam. 2004 edition with extra material. Originally published 2003 by Viking. Current version published by Penguin Books Ltd, London, UK.


  1. Harrison (2008) chapter 32 "Millions of people can't be wrong about my religion". Added to this page on 2016 Dec 16.^
  2. Harrison (2008) chapter 48 "Believing is natural so my god must be real" digital location 3444.^^
  3. Harrison (2008) digital location 3077-3079,3090-3094. Added to this page on 2017 Jan 15.^^
  4. Myers (1999) p61.^
  5. G. K. Chesterton (1874 - 1936) . Quote from Illustrated London News 19 April 1930. English novelist. Quote taken from a quotations book. Try "Oxford Dictionary of Humorous Quotations" by Ned Sherrin (2008).^
  6. Moojan Momen (1999), Oliver Thomson (1993), "Traditional Religions and Abolition of the Slave Trade" by Vexen Crabtree (2003).^
  7. Wheatcroft (2004) p56 Alcuin, the most renowned Anglo-Saxon scholar of the eighth century and founder of the academy in Charlemagne's palace at Aachen. Added to this page on 2011 Feb 09.^
  8. Weatherley (1891) p68. Added to this page on 2013 Jan 07.^
  9. McConnel (1986) p666-667.^
  10. Carroll (2011) p78,92,85-86. Added to this page on 2014 Jul 01.^
  11. Carroll (2011) p194. Added to this page on 2014 Jul 01.^
  12. Added to this page on 2013 Jan 07.^^^
  13. Skeptical Inquirer (2012 Nov/Dec) article "Phrenology and the Grand Delusion of Experience" p30-38 by Geoffrey Dean, PhD.^
  14. Added to this page on 2014 Jul 01.^
  15. Added to this page on 2016 Jun 15. Goddard (1899).^
  16. The Economist (2012 Apr 14) article "Medicine and its Rivals".^
  17. The Economist (2009 Jan 24) article "Regulating alternative medicine" p35.^
  18. Goldacre (2008) chapter 5, "The Placebo Effect", digital location 1010.^
  19. Goldacre (2008) chapter 5, "The Placebo Effect", digital location 1060.^
  20. UK's National Health Service online introduction to Homeopathy on (accessed 2015 Sep 30). Added to this page on 2016 Dec 28.^
  21. Added to this page on 2017 Jan 15.^^
  22. Harrison (2008) chapter 2 "Almost everybody on Earth is religious". Added to this page on 2017 Jan 15.^

© 2017 Vexen Crabtree. All rights reserved.