The Studies Show

Is Robert F. Kennedy, Jr., just a big crank? Well, yes. But is he nevertheless correct in his specific claims about the harms of water fluoridation? It’s long been argued that it’s no longer necessary, and that it might have the scary adverse effect of lowering children’s IQs. In this episode of The Studies Show, Tom and Stuart look at the evidence.

While they’re at it, Tom and Stuart ask whether there’s evidence for several other dentistry-related claims. Regular check-ups; flossing; fillings; fluoride toothpaste—is your dentist just b**********g you about any or all of these?

[This podcast was recorded just before Donald Trump selected RFK Jr. as his candidate for US Health Secretary, but that makes the episode even more relevant].

The Studies Show is brought to you by Works in Progress magazine. If you’re an optimist who enjoys reading about how things have gotten better in the past, and how we might make them better in the future—then it’s the magazine for you. Find it at worksinprogress.co.

Show notes

* RFK Jr.’s tweet about how the new Trump administration will remove fluoride from the US water supply

* US National Research Council’s 2006 report on fluoridation

* 2023 meta-analysis on water fluoridation and IQ

* Letter co-authored by Stuart, criticising a bad study on fluoride and IQ in pregnant women and their babies

* The original study

* Review of fluoridation and cancer risk

* 2000 UK NHS review of fluoridation and cancer risk

* 2022 UK Government report on the link of water fluoridation to various different medical conditions

* 2024 Cochrane Review on fluoridation and preventing tooth decay

* Review of guidelines from the Journal of the American Dental Association

* 2020 randomised controlled trial on fillings in children’s teeth

* The Cochrane Library on the evidence for specific intervals between dental appointments (e.g. 6 months)

* The American Dental Association guidelines on flossing, and the NHS ones

* 2019 Cochrane review of RCTs of flossing

* The ADA and NHS guidelines on brushing with fluoride toothpaste

* 2019 Cochrane review on brushing and fluoride

* Claims about cardiac health being related to dental health

* Study of 1m people in Korea on cardiac health and tooth loss

* 2020 meta-analysis of cardiac and dental health

* The study included in the meta-analysis by Chen, Chen, Lin, and Chen

* Claims about dental health and cancer

* 2020 review of the literature

* 2024 Ars Technica story on dentists over-selling their services

* 2019 Atlantic piece: “Is Dentistry a Science?”

* 2013 piece in the Washington State Dental News magazine on “creative diagnosis”

* Articles in the British Dental Journal and JAMA Internal Medicine both arguing that evidence-based medicine has left dentistry behind

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

This is a free preview of a paid episode. To hear more, visit www.thestudiesshowpod.com

You might’ve noticed it: a lot of celebrities have recently been talking or writing about their diagnosis of adult ADHD. The way they discuss it, as soon as they discovered they had ADHD everything made sense: their distractibility, their difficulties following instructions, their restlessness, and so on.

But is adult ADHD a real psychiatric condition? How does it differ from childhood ADHD? And (whisper it) might some people actually be faking having ADHD? In this episode of The Studies Show, Tom and Stuart cast a sceptical eye over this very “trendy” diagnosis.

By the way, if you’re a paying subscriber, you can add the RSS feed of this podcast to your favourite podcast app so you don’t just have to access the paid-only episodes via the Substack page. You can find out how to do so at this link.

In a desperate attempt to be relevant given the US Election, Tom and Stuart dedicate this episode of The Studies Show to talking about government investment in science. How bad is it if politicians cut the science budget? Exactly how much do you get back for every pound or dollar spent on science—and how is that even calculated in the first place?

The Studies Show is brought to you by Works in Progress magazine—a journal of science, history, and technology that discusses the secrets behind human progress. You can read their published essays at worksinprogress.co, or their shorter pieces on their Substack at worksinprogress.news.

Show notes

* Nature’s editorial: “The world needs a President who respects evidence”

* Trump’s science budget cuts: NIH/EPA, CDC

* Nature’s editorial on the “surge in far-right parties” in Europe cutting the science budget

* Tom’s 2015 BuzzFeed News article on science budget cuts in the UK

* Article on Argentinian science budget cuts under Javier Milei

* Andre Geim and Nancy Rothwell’s 2024 Guardian article on how £1 of science funding gets you £12 back

* Jonathan Haskel and Stian Westlake’s book, Capitalism Without Capital

* Haskel’s 2014 paper finding a £4 return on investment for every £1 spent on science

* 2024 UK National Centre for Universities and Business report finding that £1 of science investment leads to £3-4 of private investment

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions. We’re grateful to Jonathan Haskel for talking to us for this episode; as always, any mistakes are our own.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

WoooOOOOOoooOOOOOoooo, it’s that time of year again! It’s Halloween, so it’s time for The Studies Show hosts to face their fears, and read the research from one of the weirdest areas of science, parapsychology.

This time it’s all about psychic mediums. What does it mean to test whether someone can talk to the dead? Are we any better at doing it now than we were 100 years ago at the height of “spiritualism”? And what do the most recent results tell us about the existence of the afterlife?

Happy Halloween! 🎃

This week, The Studies Show is brought to you by Semafor, the online newletter service that gives you everything you need to know about politics, business, economics, and much more in the form of email newsletters. This week we talked about Ben Smith’s newsletter on a topic that’s just as scary as Halloween: the US Presidential Election. You can find it and more excellent newsletters at www.semafor.com/newsletters.

Show notes

* Alfred Russel Wallace’s “Defence of Modern Spiritualism”

* Article on Darwin’s views on spiritualism

* Peter Lamont’s book on Daniel Dunglas Home

* Sarcastic sceptical article on William Crookes’s botched investigation of Home

* Video of James Randi debunking the medium Peter Popoff

* Ray Hyman’s classic paper on cold reading

* 2021 meta-analysis on mediumship

* New Italian mediumship paper from 2022

* 2023 review on “Is Biological Death Final?” with discussion of the Drake Equation for parapsychology

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

Philip Zimbardo, the psychologist who’s best known for running the Stanford Prison Experiment in 1971, died last week. That’s a good excuse to discuss his legacy: what did his famous experiment tell us about the power of the situation to make normal people commit evil and sadistic acts?

In this episode of The Studies Show, Tom and Stuart go back to the original report of one of the most famous psychology studies of all time, and then see how the experiment is looking after more than 50 years of discussion and debate (spoiler: not good).

The Studies Show is brought to you by Semafor. You can sign up for their variety of online newsletters that give you in-depth information in digestible chunks. This week, we discussed the Semafor Business newsletter with Liz Hoffman, which included an interview with an electric vehicle company CEO who’s making a bet, after something of a downturn, that EVs really are the future.

Show notes

* The first academic paper to describe the Stanford Prison Experiment, from 1973

* More details on the study, including the prisoners’ “rebellion”, on Zimbardo’s website

* The first critique from 2019, from social psychologists

* The second critique from 2019, from Thibault le Texier

* Zimbardo’s response to the critiques

* Zimbardo on the Abu Ghraib prison torture during the Iraq War

* Zimbardo’s cringeworthy BBC interview on the effects of videogames

* Guardian critique of Zimbardo’s videogame claims by Pete Etchells

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

This is a free preview of a paid episode. To hear more, visit www.thestudiesshowpod.com

It’s a constant source of online controversy: surrogacy. A “medical ethics” issue like this wouldn’t usually be a case for The Studies Show, except that science is often brought into the argument.

Is it really true, as anti-surrogacy campaigners claim, that both the surrogate mother and the baby suffer serious physical and psychological problems, in large part caused by the traumatic separation after birth? In this paid-only episode, Tom and Stuart find out. To listen to the full episode and read the show notes, become a subscriber at thestudiesshowpod.com.

What’s the secret of living to 100? Well, it might be living in a “Blue Zone”: one of the handful of places around the world where there are apparently loads of centenarians. Except, as has been argued recently, Blue Zones might be a load of nonsense.

In this epside of The Studies Show, relative spring chickens Tom and Stuart look at some of the recent controversies in demography. Is there a limit to the human lifespan? Did someone really live 122 years? And how could researchers not have noticed the glaring problems with the whole idea of Blue Zones?

The Studies Show is brought to you by our new sponsor: Semafor. They’re a purveyor of high-quality newsletters offering in-depth information in digestible chunks (and they happen to be Tom’s employer). This week, we looked at Semafor Technology, in which Reed Albergotti interviewed will.i.am on AI and the future of music.

Show notes

* “Millions Now Living Will Never Die”

* Nature paper on “Evidence for limits to the human lifespan”

* Stuart’s response letter

* Saul Newman’s critique

* Guardian article and Retraction Watch article on the resulting controversy

* 2020 New Yorker article on Jeanne Calment, the 122-year-old woman

* 2004 paper on “Blue Zones”; 2013 paper

* Blue Zones website and “Live to 100” cookbook

* Blue Zones food guidelines

* Saul Newman’s paper (2024 version) critiquing Blue Zones and supercentenarian research

* Saul Newman wins the Ig Nobel Prize

Credits

* The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

There are an awful lot of things to worry about in the world. Are “superbugs” among them? That is, how worried should we be that bacteria will develop resistance to our best antibiotics, meaning infections will run rampant and even basic surgery is out of the question?

In this episode of The Studies Show, Tom and Stuart wash their hands and then dig in to the evidence on the coming antimicrobial crisis. Exactly how many deaths can we expect from untreatable resistant infections? Turns out the question is, ahem, resistant to easy answers. (Sorry).

The Studies Show is brought to you by Works in Progress magazine. Every issue, every article, gives you a new perspective on a topic you thought you knew about, or a totally new topic to think about. In their most recent issue, you can read about inflation, ancient scrolls and AI, genetic engineering, and the evolution of coffee. We’re grateful that they support the podcast; you can read their whole site for free at worksinprogress.co.

Show notes

* Andreas Bäumler on “the coming microbial crisis”

* Possible source for how many people used to die in surgery

* BMJ article on the evidence (or lack of) showing that completing an antibiotic course is necessary

* Satirical post on how the length of a course is calculated

* Our World In Data on how many people die from cancer each year

* UK Government review of antimicrobial resistance (from 2014), giving the 10m figure.

* More mentions of 10m here (NHS), and here (Guardian)

* 2016 paper in PLOS Medicine criticising the modelling that led to the 10m figure

* September 2024 paper in the Lancet with a more up-to-date calculation

* EU report on how MRSA rates dropped

* Article on the wildly successful UK attempt to cut MRSA infections

* Study on how many antibiotics are in the clinical “pipeline”

* Thread on studies showing that using antibiotics prophylactically cut child mortality in sub-Sarahan Africa by 14%

Credits

* The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

Been feeling a little strange lately? A bit impulsive, maybe? Feeling a sudden urge to get a pet cat? Sorry to say it, but maybe you’re infected with a scary mind control parasite: specifically, the paraside Toxoplasma gondii.

Or… maybe not. It turns out that, despite popular belief, the supposed behavioural effects of T. gondii are supported by very weak scientific evidence. In this episode of The Studies Show, Tom and Stuart explain.

The Studies Show is sponsored by Works in Progress magazine. It’s the no.1 destination online if you’re interested in “Progress Studies”: research on how things got better in the past and might get better in future. Whether it’s medical technology, construction materials, or policy innovation, you can read detailed essays on it at worksinprogress.co.

Show notes

* Alex Tabbarok’s review of Parasite, arguing people took the wrong lessons from the film

* Zombie ant fungus description

* Theory for how the horsehair worm affects its host

* Scepticism about whether it involves “mind control”

* Description of acute toxoplasmosis

* Tiny study on rats and cat urine

* Well-cited (but also tiny) PNAS study on rats, mice, and cat urine

* Review of toxoplasma and behavioural effects

* Very useful sceptical article about toxoplasma’s effects on rodent and human behaviour (source of the quotes on Alzheimer’s)

* Another (somewhat older) sceptical article

* Study on getting humans to smell cat (and other) urine

* Preprint on (self-reported!) toxoplasma infection and psychological traits

* Initial, smaller entrepreneurship study

* Later, larger entrepreneurship study (from Denmark)

* Meta-analysis on whether childhood cat exposure is related to schizophrenia

* Dunedin Cohort Study paper on toxoplasma and life outcomes

* “The Toxoplasma of Rage” on Slate Star Codex

Credits

* The Studies Show is produced by Julian Mayers at Yada Yada Productions.

This is a public episode. If you’d like to discuss this with other subscribers or get access to bonus episodes, visit www.thestudiesshowpod.com/subscribe

This is a free preview of a paid episode. To hear more, visit www.thestudiesshowpod.com

A while back, The Studies Show covered the question of whether smartphones and social media cause mental health problems. Amazingly, that podcast didn’t settle the issue, and the debate has continued—and continued rather acrimoniously.

Psychologists—most notably Jonathan Haidt—are currently laying into each other, analysing, re-analysing, and meta-analysing datasets to try and work out whether “it’s the phones”. In this paid-only episode of The Studies Show, Tom and Stuart explain the story so far, and in the process get very disappointed by their heroes.

If you want to hear the whole episode and read the show notes, it’s easy to become a paid subscriber at thestudiesshowpod.com.