Science vs. Pseudoscience - Siska De Baerdemaeker

350,827 views ・ 2023-07-25

TED-Ed


Please double-click on the English subtitles below to play the video.

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In the late 1700s, a German doctor named Samuel Hahnemann began publishing
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articles about a new treatment approach he called homeopathy.
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Hahnemann’s theory had two central hypotheses.
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First, the treatment for an ailment should be a dose of something
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that might cause that ailment.
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And second, diluted medicines are more powerful than concentrated ones.
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So, a homeopathic remedy for insomnia
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might include an extremely diluted solution of caffeine.
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Over the following 300 years,
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numerous physicians and patients turned to homeopathy,
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and entire hospitals were built to focus on homeopathic treatments.
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But despite all this, many studies have shown that homeopathy
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has no therapeutic effect,
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and homeopathic treatments often perform no better than placebos.
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So why do so many practitioners and institutions
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still support this practice?
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The answer is that homeopathy is a pseudoscience—
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a collection of theories, methods, and assumptions
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that appear scientific, but aren’t.
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In the worst cases, pseudoscience practitioners encourage this confusion
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to exploit people.
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But even when they’re well-intentioned,
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pseudoscience still prevents people from getting the help they need.
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So how are you supposed to tell what’s science and what’s pseudoscience?
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This question is known as the demarcation problem,
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and there's no easy answer.
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Part of the issue is that defining science is surprisingly tricky.
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There's a common idea that all science should, in some form or another,
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be related to testing against empirical evidence.
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But some scientific activities are primarily theoretical,
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and different disciplines approach empiricism
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with varying goals, methodologies, and standards.
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20th century philosopher Karl Popper tried to solve the demarcation problem
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with a simple rule.
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He argued that in order for a theory to be scientific
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it must be falsifiable, or able to be proven wrong.
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This requires a theory to make specific predictions—
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for example, if you’re theorizing that the Earth revolves around the Sun,
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you should be able to predict the path of other celestial bodies in the night sky.
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This could then be disproven based on whether or not
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your prediction corresponds to your observations.
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Popper’s falsification criterion is a great way
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to identify pseudoscientific fields like astrology,
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which makes overly broad predictions that adapt to any observation.
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However, falsification alone doesn't completely solve the demarcation issue.
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Many things we now consider science were once untestable
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due to a lack of knowledge or technology.
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Fortunately, there are other factors we can use to identify pseudoscience,
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including how a field responds to criticism.
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Scientists should always be open to the possibility
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that new observations could change what they previously thought,
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and thoroughly disproven theories should be rejected in favor of new explanations.
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Conversely, pseudoscientific theories are often continually modified
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to explain away any contradictory results.
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This kind of behavior shows a resistance
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to what philosopher Helen Longino calls transformative criticism.
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Pseudoscientific fields don't seek to address their internal biases
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or meaningfully engage in transparent peer review.
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Another key marker of science is overall consistency.
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Science relies on a network of shared information
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that ongoing research develops across disciplines.
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But pseudoscience often ignores or denies this shared pool of data.
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For example, creationists claim that animals didn’t evolve
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from a common ancestor,
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and that Earth is less than 20,000 years old.
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But these claims contradict huge amounts of evidence
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across multiple scientific disciplines,
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including geology, paleontology, and biology.
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While the scientific method is our most reliable tool
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to analyze empirical evidence from the world around us,
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it certainly doesn't reveal everything about the human condition.
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Faith-based beliefs can play an important role in our lives and cultural traditions.
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But the reason it’s so important to draw a line
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is that people often dress up belief systems as science
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in efforts to manipulate others
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or undermine legitimate scientific discoveries.
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And even in cases where this might seem harmless,
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legitimizing pseudoscience can impede genuine scientific progress.
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In a world where it's increasingly difficult to tell fact from fiction,
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it's essential to keep your critical thinking skills sharp.
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So the next time you hear an amazing new claim,
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ask yourself:
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could we test this?
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Are the individuals behind this theory updating their claims with new findings?
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Is this consistent with our broader scientific understanding of the world?
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Because looking scientific and actually being scientific
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are two very different things.
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