Debunking Denialism

Defending science against the forces of irrationality.

Category Archives: Miscellaneous

Fighting Against Dark Willow

Dark Willow

Can the acclaimed television show Buffy the Vampire Slayer teach us something about scientific skepticism when the stakes are high?

Willow Rosenberg was a core character of the show and appeared in all episodes from the very first to the very last one. Starting off as a shy and nerdy girl with poor self-esteem, she made a massive transformation as the show progressed.

Willow became a complicated and multifaceted character that combined high-level analytic ability, a struggle with balancing great magical powers to fight evil with the ever-present risk of letting it go out of hand and turning evil herself. Throughout the show she met and fell in love with Tara and they became one of the first female couples on American television.

Who is Dark Willow?

Tara was truly the light in Willow’s life, but their relationship was cut short when Tara was killed by a stray bullet fired from season six villain Warren Mears. With the death of her loved one, Willow let go of all inhibitions, allowed herself to become filled with fury and rage and completely gave into her dark magic addiction. She went to the magic shop and absorbed all of the dark magical knowledge from the books there, turning her hair jet black and the. She sought out Warren and two others who she felt was responsible for the death of her girlfriend. After managing to flay Warren alive, Buffy and her friends tries to protect the two remaining, fearing that Willow has gone fully batshit.

From a skeptical context, Dark Willow might be taken to symbolize a family or friend who has fallen to the dark side of quackery and pseudoscience. Someone who has been through difficult trauma and was vulnerable enough to be exploited by unscrupulous charlatans such as alleged psychics, astrologers or alt med proponents. She is not truly evil like some other villains of the show and sometimes you need to stand up to a friend and save them from a horrible fate.

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Introducing Knowledge Conquest

Knowledge Conquest

Debunking Denialism is proud to unveil a new companion website called Knowledge Conquest!

It was launched earlier this month with close to 150 original posts at launch. The basic idea is to gather free and high-quality science, math and coding resources. Not just any resources, but the best textbooks, video lectures, lecture notes, websites and original tutorials that can be found.

A lot of people with a burning desire to learn more about physics, chemistry, biology or psychology do not have access to high-quality learning materials due to cost of textbooks, not knowing where to begin or other issues.

It is certainly true that knowledge itself is not enough to defeat pseudoscience and the idea that people will abandon it if they only would learn more science is a much too naive position to have. However, with the growing threat of a post-fact society and dark forces on the horizon, it is important to boost the signal of good science and reduce to noise of pseudoscientific ignorance.

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DDT Apologists Promote Anti-Environmentalist Pseudoscience

Stockholm Convention

DDT was a pesticide that was indiscriminately used in agriculture before researchers understood that it had negative effects on the environment and human health. After the publication of the book Silent Spring by Rachel Carson in 1962, more and more people became aware of the problems with excessive use of pesticides and it was banned in the United States in 1972. It could still be used for the prevention of human diseases that were transmitted with the help of mosquitos and this acceptable use is still respected among global agreements on pesticides. These bans and agreements were primarily against indiscriminate use in the environment.

However, DDT apologists falsely claim that the ban against DDT led to the deaths of tens of millions of people in malaria and that environmentalism is therefore a dangerous ideology with blood on its hands. This article shows that Carson did not want to ban DDT in Silent Spring, that the EPA ban was only for the U. S. and had an exemption for public health issues, that the Stockholm Convention on Persistent Organic Pollutants also allows DDT for malaria prevention and that even the WHO recognizes and encourages this. The anti-environmentalist myth about Rachel Carson and DDT is dangerous misinformation and toxic pseudoscience.

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The Astonishing Quackery of the Natural Birth Movement

Orgasmic birth nonsense

There are few large areas in modern life that has not been infested by pseudoscience and quackery. From quantum woo and fake bleach ‘treatments’ for autism to genocide denial and conspiracy theories about mass shootings, it seems to be all around us.

One of the greatest achievements of modern medicine is reducing maternal mortality during childbirth. This has, to a large degree, been due to increased understanding about pathogens and how they are spread as well as how to handle incidents during childbirth with medical competence. Yet birth has not escaped the long reach of pseudoscientific nonsense.


Some people who reject the modern world that science has built and prefer to have a planned homebirth. Compared with hospital births of the same risk, planned homebirth triples neonatal mortality rates and 10x increased the risk of a 5 minute Apgar score of 0.

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The Pseudoscientific Disaster of Forced Anal Examinations

Dignity debased

Many governments criminalize homosexuality and consensual same-sex sexual behavior. At the time of this writing, it is illegal in over 70 countries according to the International Lesbian, Gay, Bisexual, Trans and Intersex Association (ILGA). This is typically due to religious extremism and scientific ignorance. Many religious scriptures and societies are notoriously anti-gay and some of these societies invent invalid and pseudoscientific ideas about the nature, origin and content of homosexuality, as well as supposed “spiritual harms” and fake “cures”.

Governments who criminalize homosexuality has to have a system for detecting gay men to give the appearance of legitimacy. Besides the usual techniques (such as surveillance, interrogation, and urging people to report their family, friends and relatives to the police) some of them have invented pseudoscientific methods for “detecting homosexuality” through anal examinations of the gross morphology of the anus or anal tone. It is essentially based on the same myth as virginity tests, which is the notion that penetration makes you have a loose vagina or anus. This is not true because tightness is largely under the control of the autonomous nervous system and depend on how relaxed and sexually aroused you are.

Due to the nature of these examinations and the risk to the person being subjected to it, it is typically done by force and without informed consent. Needless to say, forced anal examinations are based on pseudoscience and violates many ethical, legal and moral principles. This post surveys the arguments and evidence discussed in the paper called Statement on Anal Examinations in Cases of Alleged Homosexuality by the Independent Forensic Expert Group. More information about forced anal examinations and the eight countries where it happens can be found in this news item from International Rehabilitation Council for Torture Victims or this Human Rights Watch primer and this Human Rights Watch report. Cached version of the paper and the report can be found here and here.

Eight scientific reasons for why forced anal examinations do not work

So what are the scientific reasons for why forced anal examinations do not tell you anything reliable about anal tone or consensual, same-sex anal sex? Why should it be considered pseudoscience? Here are eight distinct reasons:

(1) There is no standardized and quantitative method for doing anal examinations of anal tone or appearance.

(2) There is no evidence that this method is valid, i.e. that certain level of anal tone or appearance is associated with receptive, same-sex anal sex.

(3) There is a certain degree of normal variability in anal features between individuals and examinations, which makes it hard to make claims about clinical relevant deviations.

(4) There is no evidence of interrater reliability i.e. that different examiners reach the same results and same interpretation of the results. Different examiners can differ in size of fingers, amount of lube used, penetration depth or the ability to digitally sense tone.

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Mailbag: Comment Spam, Geoengineering and Chemtrails

mailbag letter

It is time for another entry in the mailbag series where I answer feedback email from readers and others. If you want to send me a question, comment or any other kind of feedback, please do so using the contact form on the about page.

A really annoying aspect of combating pseudoscientific nonsense on the Internet is that within a relatively short time period, a skeptic soon starts to know more about a specific denialist claim than the denialists themselves. This is because the denialist, of course, just knows what he or she knows, but the skeptic is exposed to many denialists that put forward different patches of the same conspiracy theory or claim in question. Since there is no independent way to support pseudoscientific nonsense (no repair mechanism), it mutates as it is spread around the Internet. Together with the fact that very few new arguments are used by denialists (since they often just recycle old claims), this means that, sometimes, the crank or quack makes a claim that is just incoherent and the skeptic is forced to figure out which precise claim the denialist was referring to. Sometimes, this is just a matter of confusing some minor detail, but in other cases there is so much disconnect between the original pseudoscientific argument and the way it is delivered by a crank on the Internet. Most of the time, it is somewhere in between.

This was the case for a reader comment left by someone calling themselves Jennie. It was left on a Facebook post about the deceptive tactics used by alleged psychics, but it had to do with something completely different, namely chemtrails and geoengineering:

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Newcomb’s Paradox, One-Boxing and the Marginal Utility of Money

Newcomb's paradox

A very intelligent artificial intelligence (AI) presents you with two boxes: box A is transparent and box B is painted with a thick coat of black paint. Box A always contain 1k USD. Box B can either contain 1M USD or nothing. Do you choose to take both boxes, or just box B? Before you select your option, there is an added complication: before you get to pick, the AI has made a very, very accurate prediction about your choice. If you decide to pick just box B, you’ll get 1M USD if the prediction was correct, and 0 if it was wrong. If you decide to pick both and the prediction was accurate, you 1k. If you pick both and the AI was wrong, you get 1M+1k.

So what do you choose? The problem might seem intuitively obvious for most people. The major problem is that a considerable proportion of people thinks it is obvious that you just take box B, whereas another sizable proportion think that you should take both boxes. How can that be? This tricky situation is known as Newcomb’s paradox (or problem) and was initially put forward by philosopher Robert Nozick in the late 1960s.

The standard payoff matrix

So let us create a 2×2 payoff matrix showing what amount of money you get from choosing the different options together with the different predictions made by the AI. Making a payoff matrix is an effective way to get a general overview of the consequences of different combinations of choices in game theory (or in everyday life). Both this and the alternative payoff matrix below comes from the Standford Encyclopedia of Philosophy entry on Casual Decision Theory.

                                 AI prediction
                           One-boxing    Two-boxing
Your      One-boxing    |     1M      |       0      |
Choice    --------------|-------------|--------------|
          Two-boxing    |    1M+1k    |       1k     |

So should you one-box (only take box B), or two-box (take both box A and box B)?

The conflict

Well, the central issue here is that the Newcomb’s paradox attempts to provoke a conflict between two decision principles.

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How to Catch a Serial Killer

How are serial killers caught?

Crime shows and police procedure dramas (like Criminal Minds and Law and Order) that flood our television experience give the appearance that serial killers are caught by the use of criminal profiling and sophisticated forensic tools such as fingerprint analysis, DNA technology, digital tracking, blood spatter analysis, ballistic comparisons and many more. But how much of it is real? Are criminal profiling and forensic science really responsible for capturing most serial killers?

White, Lester, Gentile and Rosenbleeth (2011) investigates this question by studying 200 serial killers. They found that although forensic evidence was often key in getting a conviction, no serial killer was captured by the use of forensic evidence or criminal profiling. Instead, the reason serial killers were caught was traditional police work and communication with the public.

What is a serial killer?

For the purpose of this paper, a serial killer is defined as:

a person who has killed at least three people at different locations with a ‘cooling off’ period between the killings”

Special accommodations were made for a minority of repeated killers who killed at home (Gacy and Dahmer) or at a hospital (angel of death). This is different from a mass killer or mass shooter who, depending on definition, kills 3-4 people in the same general location and time.

What was the sample size and how was the sample selected?

A total of 200 serial killers were included in this study. Facts about the serial killers in the sample was taken from “newspaper reports, true crime books, and encyclopedias” and then “referenced with other sources”. The identity of these “other sources” are left unspecified.

What role did criminal profiling / forensic science play in catching serial killers?

None of the serial killers were identified or captured by criminal profiling or forensic science alone. Not a single one. The authors write:

Interestingly, not one serial killer in the present study, albeit limited to 200 subjects, was captured by forensic evidence alone, without the help of the public or the investigative acumen of the police by interviewing the public.

It should be noted, however, that forensic science such as DNA evidence, often played a crucial role in attaining a conviction against the serial killers in this sample. Thus, in contrast to police procedural dramas such as Criminal Minds, criminal profiling and forensic evidence plays a minor role in identifying and finding serial killers.

How are serial killers caught?

So if criminal profiling and/or forensic evidence does not play a leading role in identifying and capturing serial killers, how are they captured?

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The Poisonous M&Ms Analogy Metastasizes to the Syrian Refugee Crisis

Syrian refugees are not M&Ms

Most people understand that unfair generalizations about e.g. ethnic and sexual minorities are unreasonable. Yet some people attempt to give their bigoted generalizations a thin veneer of supposed intellectual credibility in order to desperately cling to their flawed and simplistic worldview. One such attempt that exploded onto Internet forums and social media in the middle of 2014 is the so-called Poisonous M&Ms analogy.

Now, with the help of politicians, authors, bloggers and other commentators, this nonsense has metastasized to the Syrian refugee crisis. People who are fleeing for their lives from terror and dictatorship are being likened to potentially dangerous pieces of candy in order to make cheap rhetorical points. However, these points crumble at a slightest hint of critical analysis.

What is the “Poisonous M&Ms” analogy and why is it fatally flawed?

The basic “argument” goes something like this:

You say that I am overgeneralizing about [group X]?

Imagine a bowl of M&Ms. 10% of them are poisoned. Go ahead, eat a handful of them. After all, they are not all poisonous!

The idea expressed above is this: just as it makes sense to not want to eat M&Ms if some of them are poisoned, it is also allegedly reasonable to make sweeping generalizations about group X. In reality, of course, it is just a clever intuition pump crafted to deflect criticism of bullshit overgeneralizations that have little to no empirical merit.

It does not require a lot of thought to find major flaws in this analogy: it has no specificity and can be applied to any group (including the group making the generalizations to begin with), it uses non-empirical base rates, the correct base rates is never factored into the analysis, it uses an irrational risk analysis that assumes that zero risk is possible and has several other flaws that was discussed in the original post linked above (that also shows some examples of this analogy being applied to African-Americans by members of the white supremacist website Stormfront).

How the Poisonous M&Ms Analogy has Metastasized

During the past few weeks, this analogy has been picked up by well-known politicians, political commentators and others. Here are a few examples to show the broad influence it has gotten:

Mike Huckabee: On MSNBC’s “Morning Joe” (Nov 17th), Huckabee compared Syrian refugees to peanuts: “If you bought a five-pound bag of peanuts and there were about ten peanuts that were deadly poisonous, would you feed them to your kids? The answer is no.”

Although not using specifically M&Ms, Huckabee deployed a version of this flawed analogy to Syrian refugees. As many have pointed out already, his base rate is way off target and both peanuts and guys named Mike have killed more people in the U.S. than refugees or Salafi jihadists have.

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How Online Casinos Deceive You Into Playing

Online Casino

How do online casinos continue to profit millions of dollars per year? What statistical, psychological and marketing tactics do they use to convince people to give up their hard-earned money for a few moments on slots with flashing lights and music? They do this by exploiting human cognitive biases, the neurobiology of reward, clever marketing tactics and the widespread ignorance of statistics.

This post will examine the mathematics, cognitive psychology, neuroscience and advertisement behind how many online casinos get people to play their salary and sometimes their entire saving away. In the end, the only way to win is not to play. If you visit Las Vegas, spend your money on good food, exciting activities and entertaining shows.

Gambler’s ruin: players can never reliably beat the casino regardless of betting system

A lot of gamblers think that they have found a betting system that allows them to get an edge over the house. The trouble is that no such betting system actually exists. This is because casinos have engineered their system to always give the house an edge over the player. A common betting system is known as the martingale system. It is based on the idea that if you lose, you double your bet. If you win, you are back over break even and reduce the bet down to the baseline again. However, simple mathematics shows that this is not a sustainable system. If you start by betting $5, then it only requires 10 losses before you are forced to bet $5120. On the 11th loss, it is $10240. Most gamblers do not have this kind of money, and will soon run out. Furthermore, a lot of casinos have a maximum limit for bets, so you cannot apply this system beyond a certain amount.

All other betting systems have similar flaws.

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