106: The Polygraph & Dentistry History

21st May 2026

You may know the polygraph is junk science, but what is the real science of lying and what wild turns did the polygraph take to get to today? And how old is dentistry? If ancient cave men didn’t brush why do I have to? Well it turns out for good reason, and some fascinating dental […]

Episode notes

You may know the polygraph is junk science, but what is the real science of lying and what wild turns did the polygraph take to get to today? And how old is dentistry? If ancient cave men didn’t brush why do I have to? Well it turns out for good reason, and some fascinating dental science.

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Images we Talk About:
Mackenzie’s First Polygraph
Ancient Teeth Image
Dentistry Tool 1
Dentistry Tool 2
Dentistry Tool 3
Dentistry Tool 4

Timestamps:
(00:00:00) Intro
(00:06:38) The Polygraph
(01:00:33) Dentistry History
(01:49:19) Outro

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We also learn about: 2 truths and a lie, the jeremy kyle show, the first lie from the devil to eve (or when children first lie), the official stance of the podcast is lying is good and cool, deontic reasoning and theory of mind, flexible and explicit TOM, Ella aces the Sally-Anne test, discovering new advanced levels of lying, lying is normal for kids it’s not evil, lying is complex… but what if it wasn’t and we could just know, James Mackenzie’s original polygraph, the polygraph actually worked (just not for lying but for cardiology), sphygmomanometers, proto-feminist William Marston, back then just thinking women had a theory of mind made you a proto feminist, Tom falls down the rabbit hole of Marston’s feminism, what’s the difference between a lie you believe and the truth, Marston is the first to bring the polygraph to court in Frye vs the United States, the polygraphs turns into a one band band machine, Marston invented wonder woman and the lasso of truth, table the feminism of wonder woman another time, if corporations are people they should all go to therapy, polygraphs are still a 2 billion dollar industry, police firefighters and paramedics still take polygraphs, Caroline pre-empts the but, a polygraph is not a machine you need the interpreter, lying is useful, it’s fun to lie so who’s your favorite co-host, wow we can bond over private healthcare, dentistry asmr, tooth decay is from bacteria acid, stone age morocco acorn sweets, you can blame agriculture for cavities, fossilized plaque can give us an oral history, determining women did a job from paint in teeth, fuck I drank the paint water at least no one will know, did you say we were kissing the rats or was that my inner monologue, would you like to read the tooth worm poem? how could this possibly get to a tooth worm, most of recorded human history we believed in tooth worms, the earliest example of dentistry was a week ago, sorry it changed a week ago, an ancient beeswax filling, a 59,000 year old tooth hole, what’s a worse hyphenate than barber-surgeon, blacksmith barbers, traveling tooth pullers, so many jobs I’m glad don’t exist, a medieval dentist clown is literally someone’s worst nightmare, victorian job questionnaire, What The Eff is That, dental tools that look like weapons made in a dream, I didn’t realize until we got into this how much I hate teeth! the truth of my soul is private in Germany,

Sources:
The Emergence of Lying in Very Young Children
Marjorie Rhodes NPR
Social and Cognitive Correlates of Children’s Lying Behavior
Review of Theory of Mind in Chilren
James Mackenzie’s “The Study of the Pulse”
Mark Harris’ Great Wired Piece on Polygraphs
Matthew Brown’s Deep Dive into Marston’s Feminism
JAAPL Frye v. United States
Cornell Law Frye Standard
Harvard center for Law Brain and Behavior on the Polygraph
Scientific American on Lying

Dentistry History sources will be added soon!

In this episode...

About the show

Science communicators Ella Hubber, Tom Lum, and Caroline Roper share anything and everything interesting! Each episode they teach each other about a science topic, answer a question, and learn about a miscellaneous topic. Whether it’s temporal illusions, animals in space, or the history of fanfiction, there’s so much out there, so let’s learn everything! Join us on Discord, email us, and follow us everywhere at LetsLearnEverythingPod.com.

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