[olivermarks]

Physical decline is hugely variable and arguably primarily a function of genetics. I would also argue some people's 'mental speed' was never that great - humans are hugely variable in performance, strength and weaknesses which makes me doubt the 'until after 60' concept. I have a 92 year old mother who is very good mentally for example compared to many people half her age...

[bigDinosaur]

It'd be a hugely unethical experiment to do, but I suspect we'll have quite a bit of data coming out of areas that did full lockdowns for extended periods of time (that were enforced) over the past two years. We should, if the theory that isolation causes cognitive decline is true, see a general decline in certain populations and it should diverge from matches around the world etc.

[traceroute66]

> It'd be a hugely unethical experiment to do

Hugely unethical, but also not scientifically sound.

COVID infection itself has already been demonstrated in various papers to cause mental decline (TL;DR there seems to be a correlation between how "sick" you got and the amount of decline).

There is also the unknown of long-term post-COVID-infection consequences on the brain.

So you would have a bit of a hard time trying to seek to attribute lockdowns to mental decline. Especially, as we know, COVID can manifest itself as an asymptomatic disease.

You then have the additional question of what are you going to count the infectious isolation period as ? It would not be ethical to count it as "lockdown".

Basically it would be extremely difficult, if not impossible to achieve any sort of statistical segregation between "lockdown" and "COVID".

Thus your input data would be messy, and per the GarbageIn-GarbageOut rule, so would your "conclusion".

[bigDinosaur]

I don't agree that it's not 'scientifically sound', it just depends on what signals the data actually shows. Natural experiments are never perfect and with something like isolation it's probably impossible to ever see such natural experiments without major confounders. I don't see why that makes you abandon the idea that anything can be learned at all.

[traceroute66]

I'm just saying that in this particular scenario there would be so many if's, what if's and buts that I think you would struggle to come up with a viable methodology, let alone a viable "conclusion".

"Lockdowns" are also inherently subjective, social and difficult to study in any sort of meaningful way. Not least because different governments implemented them differently, and different populations adhered to them differently. So you'll never really get a clean dataset - and that's assuming people tell you the truth anyway about how compliant they were with the rules.

I think a more reasonable perspective would be to wait until we know more about COVID and (especially) long-COVID. Once the world knows more about the cognitive effect of COVID, then would be the time for secondary analysis on lockdowns.

Afterall, it may well be that lockdowns were more preferable to getting infected with COVID in terms of cognitive decline. Or it may be that both "options" were more or less equal in terms of decline. But for all that we need more time to study COVID itself.

[bigDinosaur]

You seem to already have the assumption that covid is worse than isolation. I'm not sure if that's true. Would you want to bet that 5 years of isolation is better than a covid infection for cognitive function? I certainly wouldn't. Where I am, many people have been isolated for quite literally about 2 years (and many are choosing to isolate further despite the official rules mostly being relaxed). I don't think it's good enough to think of isolation as a secondary effect here.