Do phone bans in schools work?

Most parents have some concerns about phone use. This is an interesting study from the UK, that investigated phone bans in schools.

The study covered 30 schools (20 had phone bans, 10 didn't), with the students aged 12-15.

Their main finding: phone bans don't meaningfully affect/improve mental wellbeing.

Basically the phone bans only reduced phone and social media use slightly, and kids still used their phones at home.

Important point: the phone bans weren't uniform or super strict in all cases -- e.g. some schools just told students keep their phones in their bags.

So we can't say that "phone bans will NEVER work". They just didn't have a huge impact, on average, in the way they were implememted in those 20 schools.

"Sugar high" is a myth?

I remember reading that "sugar high" isn't actually real! In other words, children don't actually get overexcited after eating a bunch of sugar.

I find this hard to believe!

But, here's a (pretty old - 1995) meta-analysis which is pretty clear: sugar high is probably a myth.

The meta-analysis covered 23 other studies, and none of them found a significant effect (of sugar intake and child behaviour).

I'm still somewhat skeptical though 😆. Would be interested to delve into more recent analysis and debate.

The "Marshmellow" test

I remember reading somewhere about the "marshmellow test" – the finding that: if a child could wait longer for a marshmellow (or other snack they liked), the child would be more likely to do well later in life.

Found the original 1990 experiment!

Interestingly, this 2018 study replicated the 1990 experiment.

It basically found the link (between waiting for the marshmellow and later outcomes) to be smaller than the 1990 original – especially after controlling for other factors (like family background, early cognitive ability, etc).

What does this mean?

It doesn't "debunk" the marshmellow test entirely, it just says that other factors matter more.

It seems to me the "marshmellow test" is still an interesting "proxy" test for later outcomes – but unsurprisingly, the full picture matters more.

Claim: Two Recent “Measles-Associated” Deaths May Have Been “Fabricated”

Verdict: Broadly false, but some questions remain open

“The announcement appears to have been premature, and the deaths may even have been altogether fabricated by one of the Governor's hopeful staffers. The Lancaster County Coroner says that it has no record of any measles deaths. State law requires that all measles deaths be reported to the coroner.” – RFK Jr

Governor Shapiro's unseemly rush to Lancaster County to convene a national press conference and his…

Two deaths that the Pennsylvania Department of Health called “measles-associated” have been at the centre of a political firestorm this week. RFK Jr. said these deaths may have been “fabricated,” but more broadly, disputes that measles was the cause of death.

The Two Deaths: What We Know

A great FactCheck.org post runs through the details of the deaths. In short, while few details have been released, we do know that two individuals died, that they had not been vaccinated and that they had confirmed measles infections. While we know next-to-nothing about one case, the other case has since been confirmed to have been an infant whose primary cause of death was a “traumatic laceration of the spleen.”

This child contracted measles before birth and died shortly afterwards. It’s worth noting that this child would not ordinarily have been vaccinated by this point.

One thing to note: It has been clearly confirmed by the coroner and other state health officials that the deaths were not fabricated, as RFK Jr. claimed.

The “Cause of Death” in Measles Cases

RFK Jr. said the coroner had no record of any “measles deaths,” but this is misleading on its own. In fact, most deaths from measles do not list measles as a primary cause of death. Instead, the primary cause of death is usually the specific complication leading to death. One study from the 1970s looked at this and found that only 9.9% of 454 cases actually listed “measles” as the primary cause of death.

Measles and the Spleen

Since details are only available in one case, the focus has been on that child. The coroner claimed that measles didn’t contribute to the death, because the spleen was not enlarged [3]. However, vaccine expert Dr. Paul Offit noted that this is hard to determine after a rupture, and such a rupture should have a clear explanation. This has not been settled yet.

It’s worth noting that an enlarged spleen is a known complication of measles, present in one third of all cases in a recent Polish study and 15.4% of all infant cases.

Overall, these cases were not fabricated. That said, health officials could have avoided a lot of confusion by being clearer in the way the cases were reported.

Season 17, Episode 51: 3 Ways We’re Hunting Dark Energy, Explained

Hey StarTalkians! Episode 51 of season 17 welcomed Dr. Jason Rhodes, who sat down with Neil and Paul to discuss the new Nancy Grace Roman Space Telescope and the hunt for dark energy. This took up most of the podcast, but particularly the first half:

The Hunt for Dark Energy with Jason Rhodes - StarTalk Radio

Dr. Rhodes mentions three ways the telescope will be looking for dark energy, but as is often the case, it was easy to get lost in the meandering discussion. So here’s a briefer, clearer list.

Method 1: Type 1a Supernovae

This was discussed early on in the history of this board, but the short version is: these supernovae are “standard candles,” which are used to fix cosmic distances. If you fix the distances of many of these across different redshifts, you can tell how fast space appears to be expanding.

Method 2: Baryon Acoustic Oscillations

Baryon acoustic oscillations are a little like frozen sound waves, spread out over the universe. Back when the universe was a hot, electron-baryon plasma, photons were basically trapped. They continually interacted with the plasma, until the universe cooled enough for the particles to form into the first atoms. At this point, the photons could finally escape, leading to the well-known cosmic microwave background radiation (CMB).

But at the same time, the ripples of what happened in the plasma phase spread out too. Denser regions of the early plasma universe were pulled together by gravity, but pushed back apart by the interacting photons. This led to oscillations – like sound waves – which travelled through the plasma until the universe cooled.

These waves were released along with the CMB, and form another key relic of the early universe. A distinctive signal of this has been detected.

Like type 1a supernovae, these can be used to establish a distance scale, and any distance scale can be used to probe dark energy.

Method 3: Weak Lensing

Gravitational lensing is usually discussed in the dramatic cases, like a galaxy cluster magnifying and warping an ancient galaxy behind it. But it also operates on much smaller scales, and this type is useful in the hunts for dark matter and dark energy. This gets especially technical, but the short version is: weak lensing is useful in combination with the other two methods, and by helping to map the distribution of dark matter.

Does flying increase cancer risk?

Going on a tangent from another Board. We were talking about "space weather" and landed on the question of "flying and radiation".

Found this literature review found that:

aircrew have higher rates of certain cancers, such as melanoma, non-melanoma skin cancer, and breast cancer in female flight attendants, compared to the general population. However, the evidence does not clearly prove that cosmic ionizing radiation alone causes these cancers, because other factors—like disrupted sleep patterns, lifestyle, and exposure to chemicals—also affect risk.

(Quoting the Credo summary)

To me, it sounds plausible. Flight attendants, pilots, and frequent flyers beware!

[Project Credo Monthly Broadcast] July/August 2026

If you're new here, say hello and reach out to the team at [email protected]. We've been hard at work improving all aspects of the site so we put our best foot forward for anyone new to the site.

Community

A few new boards have been created to help us fill out the types of conversations we want to read about.

• Podcasts We Love | Project Credo covers a ton of interesting factoids and discussions across all the podcasts we've been listening to

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Features and Bug Fixes

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What we're working on

• Board agents: We want to enable more automation to make boards even more valuable. We're testing soon!

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Creatine for cognitive function?

Eating creatine for physical health has become an accepted thing. But what about for the brain?

A while back, I watched this Huberman Labs episode, that covered this.Huberman podcast (with guest Rhonda Patrick) And I wanted to look at the research myself: here's one 2024 systematic review, covering 16 randomised control trials with a total of 492 participants.

You can see the full methodology and results in the credo summary of the paper -- but essentially the review concluded that creatine did have benefits for cognition.

As per the credo summary tldr:

This supplement may modestly improve memory and help people complete attention and fast-thinking tasks more quickly.

Shingles Vaccine Protects Against Dementia

A flagship study came out in Nature in 2025 that solidified a long observed finding, that the Shingles (Herpes Zoster) vaccine can protect against dementia.

Previous studies were classic observational cohort designs which can fail to show causation or account for confounding factors. This 2021 study found "a combined analysis estimated a 31% lower risk" and indicated the need for stronger research.

In comes the 2025 Nature study, this time a natural experiment arose:

To provide causal as opposed to correlational evidence, we take advantage of the fact that, in Wales, eligibility for the zoster vaccine was determined on the basis of an individual’s exact date of birth. Those born before 2 September 1933 were ineligible and remained ineligible for life, whereas those born on or after 2 September 1933 were eligible for at least 1 year to receive the vaccine.

The finding:

We show that receiving the zoster vaccine reduced the probability of a new dementia diagnosis over a follow-up period of 7 years by 3.5 percentage points (95% confidence interval (CI) = 0.6–7.1, P = 0.019), corresponding to a 20.0% (95% CI = 6.5–33.4) relative reduction. This protective effect was stronger among women than men.

Interestingly, the newer recombinant vaccines seem to be ever more effective than the live-attenuated vaccines (the ones tested in the Nature experiment), though more studies are in the pipeline to deepen this finding.

The mechanism for why the protective effect happens is still TBD, though some hypothesize that detrimental impact of getting Shingles on the brain may cause long term damage that leads to dementia.

Either way, the impacts seem clear, the Shingles vaccine seems like a must-get in a full range defense against dementia.

20g of creatine to boost cognition?

On an episode of Huberman Labs, guest Rhonda Patrick talks about creatine for cognition. When she's sleep deprived, she takes 20g of creatine, and says it helps (could be placebo effect, she says).

I looked up a specific paper that mentions this 20g figure. Interestingly, the paper is a review by the European Food Safety Authority, and it reviews 21 studies.

As the credo summary highlights, the review found:

Two studies suggested short-term working-memory benefits at 20 grams daily, but lower doses and longer use did not reproduce them.

Would be interesting to deep dive into those two studies!