Are cancer rates going up or down? It seems like depending on where you look, you’ll find different answers to the question. What’s going on here — have some writers just got it completely wrong? Is it something to do with different types of cancer? Are we being confused by some kind of weird statistical artefact? All of the above? In this episode of The Studies Show, we do our very best to find out.

The Studies Show is brought to you by Works in Progress magazine, the ultimate place online to read about new and underrated scientific and technological ideas that could make the world a better place. You can find a huge range of essays online, for free, at www.worksinprogress.co.

Show notes

* BBC Future article on early-onset cancer rates

* BMJ Oncology article on global cancer incidence increasing by 79%

* And its online supplementary information

* July 2025 Economist article on how the world is winning the war on cancer

* Saloni Dattani’s 2025 article on the decline in global cancer rates

* The GLOBOCAN data update from the IARC, 2002 and 2008

* Our World in Data’s graph on global cancer incidence over time

* Their graph on smoking rates and lung cancer deaths

* Their graph on stomach cancer death rates

* New RCT on vaping and smoking cessation

* A 90% drop in cervical cancer rates in England

* The hepatitis B vaccine and a massive drop in liver cancer incidence in China

* On H. pylorii, ulcers, and cancer

* 2000 JAMA article questioning the utility of the 5-year survival rate statistic

* 2014 PLOS ONE article that’s more positive about the statistic

* Tom’s BuzzFeed News article on oncology

* RCT of herceptin on breast cancer survival

* Study on rates of colorectal cancer

* And the same, in relation to BMI

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

Seconds out! Round one! Ding ding! And other boxing terms. We’ve found a topic on which Tom and Stuart actually disagree. Kind of. In this episode of The Studies Show, they use the examples of “the worm wars” (does deworming kids in developing countries help them stay in school?) and a new craze for “tooth bacteria” (can colonizing your mouth with a genetically-modified bacterium stop you getting cavities?) to argue about how we should make our minds up about uncertain—but potentially promising—medical treatments.

The Studies Show is brought to you by Works in Progress magazine. On the show this week we discuss one of the articles in their newest issue, on “the end of lead”—the history of countries slowly removing lead from pipes, paint, and the rest, and how much work still needs to be done. Find it, and a wealth of other fascinating free articles, at worksinprogress.co.

Show notes

* Tom’s Unherd article about the Worm Wars

* The famous 2004 paper that sparked the wars

* “Deworming Debunked”, from the BMJ

* The 2014 follow-up of the original dewormed Kenyan kids

* GiveWell’s re-analysis of both studies

* And another more recent analysis by the same org

* The third study in the same kids, from 2020

* 2019 paper on “resolving the worm wars”

* Scott Alexander’s article on “defying cavity”—on the Lumina bacteria

* Guy who claims the Lumina bacteria made him go blind

* Saloni Dattani’s useful thread on Lumina

* 90% of drugs in preclinical trials don’t make it to become medicine

* Tom’s frankly cruel tweet where he refers to Stuart as “Goofus”

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

Inspired by a new Nature paper on how the “maths gap” emerges between girls and boys in school, Tom and Stuart look into the evidence for psychological sex differences: in maths, in mental rotation, and, yes—in whether they like pink or blue.

To listen to the full episode and read the show notes, you’ll need to become a paid subscriber at www.thestudiesshowpod.com/subscribe.

Whether it’s people giving themselves goat blood transfusions in an effort to maintain their youth, or yet another influencer telling you to buy XYZ miracle supplements, anti-ageing is big business.

In the first part of what will surely become a longer Studies Show series, Tom and Stuart look at the evidence for a few supposed “breakthrough” treatments that can slow down ageing: rapamycin, metformin, winding back the epigenetic clock, and calorie restriction.

The Studies Show is brought to you by Works in Progress magazine. This week we talked about their new article on “through running”—the deceptively simple idea of not having trains stop at the edge of town and instead running them right through the centre. It seems obvious if you live in London, but it wasn’t always this way. Check out the article for a detailed, nerdy discussion about how we can make trains—and therefore citites—better.

Show notes

* New meta-analysis on rapamycin and ageing

* Website for Bryan “n = 1” Johnson and his related health claims

* Our World In Data on life expectancy and about the reasons why it increased

* Meta-analysis on methylation and the “biological clock” as a predictor of longevity

* The STAP stem cell debacle

* 2016 study using Yamanaka factors to slow down ageing in mice

* 2023 study of the same idea on wild-type mice, showing a 109% increase in life expectancy

* 2014 Scottish study on diabetes, metformin, and life expectancy

* Critical letter noting the study’s flaws

* Failed replication from Denmark in 2022

* The NIH’s Interventions Testing Program

* Older review of calorie restriction and ageing

Credits

We’re grateful to Andrew Steele for talking to us for this episode. 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

Would you like to do 80% of your current job but for 100% of the pay? Well, of course you would. But would it be good for the economy? It’s been suggested that companies who move to four-day working weeks have happier, less frazzled employees and no noticeable loss in productivity. Some people even claim their productivity goes up!

In this episode of The Studies Show, Tom and Stuart explore the theory and the evidence on the four-day week. There are some ridiculously overblown claims here, but is there any realistic stuff left over?

The Studies Show is brought to you by Works in Progress magazine. As of last week there’s a new issue of the magazine, and it’s full of the usual mix of remarkable historical, technological, and scientific topics (and sometimes all three together). Find it all completely free at worksinprogress.co.

Show notes

* Pedro Gomes’ book Friday is the New Saturday

* The Chinese city considering giving everyone Friday afternoons off

* One of a few pro-4-day-week websites

* 2019 Guardian report claiming that Microsoft Japan increased productivity by 40% after implementing the 4-day-week…

* …and a World Economic Forum report claiming the same thing…

* …debunked by Microsoft Japan’s own press release

* Henry Ford: Why I Favor Five Days’ Work With Six Days’ Pay (from 1926)

* Evidence that after a certain point, extra hours become counterproductive

* 2023 UK trial into the 4-day week

* Four-year trial of the 4-day week in Iceland

* 4-day week trial (with control group) in Portugal

Credits

We’re grateful to Prof. Pedro Gomes for talking to us for this episode. 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

We all hate “urban decay”—graffiti, litter, boarded-up buildings. But does urban decay cause crime? That’s the premise of the “broken windows” theory: seeing a dilapidated and poorly-maintained physical environment emboldens criminals.

In this episode of The Studies Show, Tom and Stuart discuss the history of, and the evidence for, broken windows theory. The theory has inspired social psychologists, criminologists, and others to do an awful lot of studies—and as we’ll discover in this episode, it seems to have inspired scientists to commit a few crimes themselves…

The Studies Show is brought to you by Works in Progress magazine. In particular, it’s brought to you by this recent article on the world’s first electric grid, which is representative of the thoughtful, data-rich, well-written articles on human progress that you’ll find everywhere on the main site and its associated Substack.

Show notes

* Robert Jenrick confronts fare-dodgers on the London Tube…

* …and talks about “broken windows” in an interview afterwards

* The original “broken windows” article from The Atlantic in 1982

* Philip Zimbardo’s 1969 article, including the “Bronx vs. Palo Alto” study

* Diederik Stapel’s 2011 Science article on “coping with chaos”

* …and an article about him after his fraud was revealed

* The famous Keizer et al. study from 2008 (also in Science)

* 2014 article that’s highly critical of Keizer’s research

* 2017 failed replication of Keizer et al.

* Useful 2020 review article on the empirical evidence for broken windows theory

* 2018 Australian panel study on informal social control and crime

* Article arguing NYC had a major crime decline in the 1990s, but that it wasn’t through broken-windows policing

* Data on homicides in NYC by year

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

Hello everyone! Thanks to Tom’s holiday and Stuart’s job we weren’t able to record this week, so we’ve put out a classic paid episode to tide you over. We hope this goes some way to scratching your Studies Show itch.

Most people think it’s obvious that you should wear a helmet when cycling. It might save your life if you fall off and hit your head. Duh.

But over the years, many contrarian arguments have pushed back against this seemingly-obvious point. What if people engage in “risk compensation”, where they cycle more dangerously because they know they’re wearing a helmet? What about if encouraging helments puts people off cycling so they miss the health benefits?

In this March 2024 episode of The Studies Show, Tom and Stuart try to work out who’s right.

Show notes

* The original 1975 study on what’s become known as the “Peltzman Effect”: risk compensation (in this case about car safety)

* Potential evidence for risk compensation in AIDS

* Claims of risk compensation relating to mask-wearing at the start of the COVID-19 pandemic

* The eye-tracking study on helmet-wearing, which used the Balloon Analogue Risk-Taking lab task

* n=27 study on helmets and cycling with one hand on the handlebar

* Study on risk compensation with the following confusing structural equation model diagram:

* Academic cycles around and records thousands of cars passing him while he’s either wearing or not wearing a helmet

* Forbes article about the statistical controversy over these data

* Bizarre study on how motorists “dehumanize” cyclists

* Could helmets make “rotational injuries” worse?

* Cochrane review on cycle helmets and injuries from 1999

* Ben Goldacre and David Spiegelhalter on cycle helmets - “uncertainty… is unlikely to be substantially reduced by further research”

* Systematic review on helmet use and injuries from 2016

* Review of meta-analyses from 2023

* 2006 BMJ article finding “no clear evidence” that mandating cycle helmets reduces injuries

* Negative correlation between cycle numbers and helmet usage, across different countries

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

Can adults still grow new neurons in their brains? You’d think we might know the answer to the question of adult “neurogenesis” after more than half a century of neuroscience research. But it turns out we don’t.

In this episode of The Studies Show, Tom and Stuart look into the suprisingly controversial question of adult neurogenesis. Are you “stuck with” the number of brain cells you had as a child, or can you add to that number by making the right choices as an adult? And does it even matter?

This podcast is brought to you by Works in Progress magazine, which this week has a new article explaining why nuclear power is so expensive (spoiler: it relies on an incorrect scientific model that we’ve discussed in previous podcast episodes: the “linear no threshold” model. For a full explanation, along with articles on a dizzying array of other progress-related topics, take a look at www.worksinprogress.co.

Show notes

* Summary post on the debate by Scott Alexander from 2018

* 2000 PNAS study on the brains of London taxi drivers

* 2021 retrospective review of taxi driver studies

* Study comparing passed vs. failed cabbies on “The Knowledge”

* Study putting together neuroimaging research on when the brain peaks in volume and other measures

* 1962 Science study on neurogenesis in rats

* 1999 BrdU study in macaque monkeys

* Famous 1998 study on neurogenesis in the human hippocampus

* 2006 PNAS sudy on testing neocortical neurogenesis using Carbon-14 dating

* 2013 study using similar methods on the hippocampus

* 2018 Nature paper claiming no adult neurogenesis

* Associated commentary article

* Atlantic article describing the controversy by Ed Yong

* 2018 paper finding neurogenesis occuring up to age 79

* 2019 Nature Medicine paper claiming “abundant” adult neurogenesis

* Fair-minded 2019 review paper

* Somewhat angrier 2021 review paper

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions. We’re grateful to Claire Wang for her help with researching this episode.

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

Do you know anyone who has extremely intense relationships—one minute totally in love with someone; the next, flying into a rage and calling them the worst person ever? It’s possible that they have borderline personality disorder.

Whatever that is. What is a “personality disorder”, anyway? How is one diagnosed? In this episode of The Studies Show, Tom and Stuart discuss a disorder that gets a lot of attention online, but which seems pretty tricky to define. And it’s somehow both surprising and entirely predictable that Tom relates this disorder back to his favourite topic: the Reverend Thomas Bayes.

The Studies Show is brought to you by Works in Progress magazine. On their Substack newsletter, you can find different styles of articles that aren’t part of the main magazine, like this excellent walkthrough of nuclear power technology called “Nuclear Reactors for Dummies”. You can find that and much more at worksinprogress.news.

Show notes

* Mayo Clinic page on personality disorders

* NHS page on Borderline Personality Disorder

* Chimamanda Ngozi Adichie’s 2021 essay “It is Obscene”

* Tom’s Unherd article on this controversy

* 2009 paper on Dissociative Identity Disorder and its overlap with Borderline Personality Disorder

* Comparison of patients with DID and BPD, with a discussion of the overlap

* Pieces by people with BPD diagnoses who’ve regularly changed their dress/style

* Tom’s book on Bayesianism

* Sceptical article about top-down effects on perception

* Paper on the “predictive processing” theory of BPD

* Scott Alexander article on the same topic

* Twin study on the overlap between BPD and antisocial personality disorder, and potential sex differences

* Longitudinal studies on whether people “age out” of BPD

* People higher in “dark tetrad” traits are more likely to enjoy trolling people online

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

Did you miss our live show last week? Good news if you happen to be a paid subscriber: we’re posting the audio in full. Listen as we’re joined by Jesse Singal from Blocked and Reported to discuss the strange “science” of Multiple Personality Disorder (or is it Dissociative Identity Disorder?), as well as digging into the methods of a deeply flawed paper on “top surgery” for gender-dysphoric youth.

To listen to the full show, and to read the show notes, you’ll need to become a paid subscriber at www.thestudiesshowpod.com/subscribe.