Is A Claim True? Use These 4 Criteria To Evaluate The Evidence

Witchcraft and the Danger in Believing without Evidence

Warning: Disturbing content

When a young boy complained of stomach and chest pains, his family rushed him to the doctor. Tragically, he died a few hours later.

Janet and Andrew, the boy’s mother and uncle, suspected witchcraft.  They tracked down two women in the forest, who, under torture, admitted to sorcery, but accused 20 year-old Kepari Leniata of being a witch and killing the child.  

Kepari was dragged from her home by a mob, stripped naked, and tortured with white-hot iron rods. After confessing, she was doused in oil, hands and feet bound, thrown onto a pile of trash, and burned alive in front of hundreds of onlookers.

A few years later, another girl, Nancy, fell ill. Rumors again began to circulate….. There was sorcery in the air. They captured six year-old Justice, believing she had stolen the girl’s heart. When they used hot knives to peel away Justice’s skin, Nancy seemed to recover, and when they stopped, Nancy seemed to worsen. 

They tortured Justice for five more days, waiting to see what happened to Nancy, ready to execute Justice if Nancy died.  Thankfully, Justice was rescued.

Why did the villagers suspect Justice of witchcraft? She was Kepari’s daughter.

Between 1482 and 1782, up to 50,000 people, mostly women, were executed for witchcraft. Witches were blamed for killing crops, bad storms, even birth defects, things we know today have natural, not supernatural, causes. Being accused of witchcraft was often sufficient evidence, as were “witch marks” like moles or birthmarks.

But the best evidence? Confessions. And how do you get a witch to confess? Torture.

From top left: The saw, Great Ripper, Spanish Donkey, Burn at Stake, Spiked Chair, The Rack

I can honestly say I would confess to just about anything under these circumstances. And so did many accused witches. In Germany in the late 16^th century, German farmer Peter Stumpp confessed to turning into a werewolf and eating fourteen children and two pregnant women, and midwife Walpurga Hausmännin confessed to vampirism and killing 40 children. Both claimed to have gotten their powers from the devil, and concocted elaborate details of their supposed crimes, likely to escape the horrific torture they endured.

And unfortunately (fortunately?), once you confessed, you were executed, often by being burned alive, but maybe only after being mutilated.

But Kepari Leniata didn’t live in Medieval Europe. Or even 17^th century Salem. She was tortured and executed in Papua New Guinea, in 2013.

Purported to be the burning rubbish pile on Warakum Junction Road, in Mount Hagen, Papua New Guinea, on to which 20-year-old Kepari Leniata was thrown in 2013. Photo: AFP. https://www.executedtoday.com/2018/02/06/2013-kepari-leniata-burned-as-a-witch/

And she’s far from alone. Across the world today, from Sub-Saharan Africa to South Central Asia, to the Amazon, belief in witchcraft is prevalent, and hundreds of people, mostly women, are executed each year. Today.

I apologize for traumatizing you with these stories. I admit, I cried and felt sick to my stomach writing this. But I had reasons for doing so.  

First, there can be real harm to believing things that are not true.  Our beliefs impact our behaviors and actions. For example, those who don’t accept the dangers of COVID-19 are less likely to wear a face mask, and those who believe vaccines are dangerous are less likely to immunize their children. And unfortunately, cancer patients who believe in alternative medicine are more likely to refuse evidence-based treatments, and are more likely to die as a result. 

Second, we often aren’t as rational as we think we are. We think we follow evidence to a conclusion. In reality, the opposite is true. We come to our beliefs through irrational ways. We believe what we’re told, especially from trusted authority figures. And we believe what those around us believe. Once we believe, we work backwards to find evidence to rationalize the belief.

And we want explanations, so we search for patterns. We’re so good at finding patterns we even find non-existent ones. Then, we assume there’s an intentional, often supernatural, force behind the pattern.

Janet wanted to know what killed her child. In Papua New Guinea, nearly everyone believes in sorcery, and has for generations, and they see “evidence” everywhere for good and bad magic changing fortunes. Most lack education and proper health care, and even electricity and running water. So when sudden deaths or diseases strike, magic is blamed, and angry mobs find scapegoats for justice.

And third, evidence matters.   

Evaluating Evidence

In our search for knowledge, evidence gives us reasons to believe. In general, the more and better the evidence, the more justified we are in accepting that something is true.

While there are many ways to evaluate evidence, four useful criteria are that the evidence should be sufficient, relevant, comprehensive, and reliable.

1. The evidence must be sufficient to establish the truth of a claim.

The person making the claim bears the burden of proof, and must provide enough positive evidence to establish a claim’s truth. Claims made without evidence provide no reason to believe, and can be dismissed.

Extraordinary claims require extraordinary evidence. Essentially, the more implausible or unusual the claim is, the more evidence is required to believe it. 

Claims based on authority are never sufficient. Expertise matters, of course, but they should provide evidence.  But, “because I said so,” is never enough. 

Anecdotes are never sufficient. Personal stories can be very powerful. But they can also be unreliable. People can misperceive their experiences and be wrong. And unfortunately, people can also lie.

As an example, let’s say you own a company, and Jamie works for you. She is an excellent employee, always on time, and always does great work. One day, Jamie is late for work.

If Jamie tells you her car broke down, you most likely will believe her. You have no reason not to, although if you’re really strict you may ask for a receipt from the tow truck driver or mechanic.

But what if Jamie tells you she’s late because she was abducted by aliens? I don’t know about you, but my standard of evidence just shot through the roof. That’s an extraordinary claim, and she bears the burden of proof. If she proceeds to tell you that the aliens look like faceless octopi that communicate telepathically, that one of them took her to another dimension and forced her to bear offspring, but then reversed time to bring her back without physical changes…  Again, just speaking for myself, but I’m either going to assume she’s lying, or send her to a medical professional.

2. The evidence must be relevant to the claim.

In an attempt to support a claim, some may, either deliberately or not, use irrelevant evidence. It may sound persuasive, but if the evidence does not support the claim, it’s useless in establishing the claim’s truth.

Examples include logical fallacies of relevance, including:

• Appeals to emotion, such as to fear, anger, pride, or pity, which rely on emotionally charged language to persuade. Strong emotions can be very convincing, but they’re not evidence.

• Ad hominem attacks shift the focus away from the evidence and toward the person making the claim. Your dislike for someone, or their actions, is irrelevant to the truth of a claim.

• Appeal to the masses, which suggest that, since everyone believes something, it must be true, or appeal to tradition, which asserts that the claim must be true because people have believed it for a long time. Again, this is not evidence. People can be wrong. For a long time.

• Red herring, which occurs when someone shifts the focus away from the topic being discussed.

For example, your son failed his science exam because he spent most of the last three weeks of class playing Angry Birds on his phone. When you ask him why he failed, he says: “I know I did poorly, but have I told you lately how much I love you? That teacher is a jerk and he really hates me. Everyone in the class did poorly. Besides, I did all of my chores this week.”

This may sound persuasive, but none of it was relevant to why he actually failed his exam.

3. The evidence must be comprehensive.

Imagine all of the evidence for a claim is like a puzzle. If we stand back and look at the whole puzzle, we can see how the pieces fit together and the larger picture they create. This is called the body of evidence.

You could, either accidentally or purposefully, cherry pick any one piece of the puzzle, and miss the bigger picture.

For example, everything that’s alive needs liquid water. Water is so essential to life that, when looking for possible life outside of Earth, we look for evidence of water. The typical person can only live for three or four days without water.

But what if I told you that all serial killers have admitted to drinking water? Or that water is used in certain forms of torture? Or that it’s the primary ingredient in many toxic pesticides? Or that drinking too much water can cause the brain to swell and be fatal?

By selectively choosing pieces of evidence, we can wind up with a distorted view of reality. But if we want to better understand reality, it behooves us to look at all of the evidence.

4. The evidence must be reliable.

Evidence is essentially information that’s used to determine if something is true. However, not all information is created equal. To determine if evidence is reliable we must look at two factors.

How was the information gathered? A major reason science is so reliable is that it’s a system of collecting and evaluating evidence. (It’s also why people often use “science” or “studies” to give legitimacy to their beliefs.)  However, even scientific studies vary in the quality of evidence they provide. 

For example, studies in lab animals or test tubes provide the lowest form of evidence; uncontrolled observational studies are better, but provide correlational evidence; and randomized controlled trials provide excellent causational evidence. Because meta-analyses and systematic reviews look at the big picture, they provide the best type of evidence.

What is the source of the information?  Sources really matter. We are drowning in information these days, and not all of it is reliable. 

In general, the most reliable sources are peer-reviewed journals, because like the name suggests, the information had to be approved by other experts before being published. Next most reliable would be the high-quality journalistic outlets that have a track record of accurate reporting. 

The least reliable sources are personal stories, because people can misinterpret their experiences. (They can also lie.) And it’s important to keep in mind that anyone can create YouTube videos, FaceBook memes, Twitter threads, or even blogs. 

(Learn more: Don’t be fooled… Fact Check!)

The unfortunate case of Kepari and Justice

Let’s circle back to Kepari and her daughter.

Janet claimed that Kepari used witchcraft to kill her child. Janet’s reasons, or evidence, included the fact that she lived next door, her child died, and two women accused Kepari  of witchcraft under torture.

Janet bears the burden of proof for this claim, and the claim of witchcraft is an extraordinary claim, as there is no scientific evidence for the existence of sorcery. In addition, confessions from torture are not reliable. Many of the accused witches throughout history have concocted wild, intricate stories, from flying through the air to wild orgies with the devil. Anecdotes are insufficient evidence for a reason, and these stories are almost certainly stories told to escape excruciating torture.

In addition, the fact that Kepari lived next door is simply a correlation, and not sufficient evidence to demonstrate that Kepari committed murder. The same is true for Justice, whose crime was being the daughter of another supposed witch.

The take–home message

This unfortunate story is a reminder that we aren’t as rational as we think we are. Many of our beliefs are influenced by our culture and geography, and not the result of evidence-based thinking. Belief in witchcraft is less common in wealthy countries, but there’s a good chance that you have beliefs that are just as irrational. 

Demanding evidence is foundational to critical thinking, whether it’s evaluating claims of others or our own beliefs. But no one can fool us as much as we can fool ourselves, and if we’re looking for evidence, we will find it. 

So ask yourself: What is the source of this belief?

Then, evaluate the evidence: Is it sufficient? Is it relevant? Is it comprehensive?  And is it reliable?

If we want to align our beliefs with the truth, it’s essential that we question ALL of our beliefs. If it’s true, if it will survive being questioned. 

And importantly, if the evidence suggests we’re wrong, we should be open to changing our minds. 

To Learn More

Los Angeles Times, Murder Charges Filed after Woman Burned Alive in Papua New Guinea
Post Magazine, In Papua New Guinea, Witch Hunts, Torture, and Murder Are Reactions to the Modern World

Thanks to John Cook, Lynnie Bruce, and Anthony Trecek-King for their feedback.