Catching Covid Does Not Lower Your IQ
Back in March, I wrote about a study that was widely touted as showing that catching Covid lowers your IQ. The study found that individuals who’d had symptoms for more than 12 weeks scored about 6 points lower than those who hadn’t caught the virus. Even individuals who’d had an asymptomatic infection, the study found, scored about 2.5 points lower than those who’d never had one.
However, I was sceptical that these findings were explained by Covid having a large negative impact on cognitive ability.
The authors didn’t actually look at change in IQ scores, but rather at the cross-sectional association between Covid infection and IQ scores. Hence their findings could easily be explained by self-selection: people with higher cognitive ability may have been less likely to catch Covid, and may have been less likely to get seriously ill when they did catch it. As evidence, I noted that such people tend to work in professions that had lower risk of exposure to Covid, and tend to be healthier in general.
A new study has confirmed my suspicions: it appears that catching Covid doesn’t lower your IQ after all.
Bas Weerman and colleagues analysed data from the Understanding America Study – an ongoing longitudinal survey with a large sample size that began in 2014. As part of the survey, respondents complete a series of cognitive tests every two years. In March of 2020, they completed a questionnaire about the emerging Covid pandemic, in which they were asked whether they’d ever tested positive for the virus or been diagnosed with the disease by a healthcare professional. Around the same time, they were invited to participate in separate bi-weekly surveys, which also asked about their infection status.
The researchers therefore had data on respondents’ test scores before the pandemic, their infection status during the pandemic, and their test scores after they’d been infected (for those who had). This allowed them to test whether Covid infection was associated with a decline in test scores between the pre- and post-Covid waves of the survey.
Weerman and colleagues began by replicating the finding of the earlier study – that individuals with lower test scores measured before the pandemic were more likely to become infected. They then looked at whether individuals who became infected subsequently scored lower on the cognitive tests, and found they did not. Eight separate measures of cognitive ability were included in the study, and none of them was affected by Covid infection.
Together, these two findings strongly support my interpretation of the earlier study: self-selection is what explains the association between Covid infection and IQ scores. Rather than Covid infection causing lower cognitive ability, it appears that higher cognitive ability caused people not to catch Covid (or to catch the later, milder variants).
All those headlines about Covid making you less intelligent – about even mild infections knocking several points off your IQ – turned out not to be true. Given the media’s general tendency to exaggerate, overhype and sensationalise the threat from Covid, I wouldn’t expect this new study to get nearly as much coverage as the earlier one.
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Gosh I must live in a clever spot as I am surrounded by boostered folk who seem to catch ‘Covid’ every few weeks and wish to tell me every one of their symptoms.
Can you even catch the same virus twice?
You can if you’ve been well jabbed and boosted, apparently!
So maybe it’s the other way around. A low IQ makes you more susceptible to catching covid, via a jab impaired immune system.
Btw, can anyone tell me what Covid is? I literally have no idea what it is.
Covid = Coronavirus Disease. That is a group of symptoms caused by coronaviruses aka Common Cold. 10% of Colds are caused by coronaviruses, and other respiratory viruses.
Symptoms may include some of the following: nasal discharge; sneezing; raised temperature; fatigue; sore throat; cough; headache; aching muscles.
So-called CoVid 2019 is just like Covids of any other year except caused by a particular “new” coronavirus that may/may not have been manufactured. Giving it a special name meant they could claim it was like nothing ever encountered before… so panic! Lockdowns, masks, jabs.
“Btw, can anyone tell me what Covid is? I literally have no idea what it is.”
That’s a very good question. The term is somewhat meaningless, IMO – it covers a list of symptoms so long and so vague that overlap with lots of other existing ailments that I just don’t see what it conveys. If you believe that LFTs and PCR tests are accurate then I suppose that means that a specific virus has been identified inside you, but even if you believe that, the effect it has on people seems to vary so much that I am not sure what the point is of the test, given that there is no recognised treatment.
In the very early days there did seem to be a few people in whom “covid” triggered a cytokine storm (immune system overload) which was sometimes deadly, even in less frail people. These may be the only people who actually died FROM covid. I’m not aware that similar respiratory diseases do this – perhaps they do sometimes and I just never really paid attention before because it’s so rare.
In short, I think for all practical purposes it’s just a new name for colds/flu.
If you change “covid” for “a cold” pretty much anything that is said or written about it looks ridiculous.
Indeed. The whole business from the beginning until now still strikes me as utterly surreal.
People keep telling me they “have covid” and I tell them that if it exists I must have had it, as I have been “ill” since “covid” was a thing, but that doesn’t seem to register with people. I’ve never taken a “covid test” so it doesn’t count!
I have noticed amongst my acquaintances, that those who keep getting Covid are the ones clamouring for their shots and still wearing masks at the least provocation. One was a pharmacist who of course assures us that that makes her an authority.
Almost everyone I know has been “vaccinated” and has also “had covid” (taken a “covid test”) multiple times. The tiny number of people I know who haven’t been “vaccinated” don’t test and I suppose have had the usual minor ailments which may or may not have been “covid” (if it exists).
It does. At the moment, both of my ears are pretty much swollen shut. That’s the meanwhile traditional parting shot from the summer COVID wave and while they only hurt very occasionally, my hearing is pretty impaired. And that’s a typical COVID thing: low-key symptoms wich can take weeks to clear and are thus seriously annoying. I didn’t have this prior to 2019.
Judging from anecdotical evidence, ie, stuff I hear from my few relatives, friends and acquaintances, vaxxed people seem to have a much harder time getting through with this: Two of them ended up in A&E because of (subjective) symptoms resembling a heart attack and there was also one case of an unusually drawn-out minor pneumonia.
This can probably be a real horror to people who are prone to worrying about their health very much because it takes so long to go away. Which suggests that the pandemic as we were forced to experience it was probably mostly a few thus vulnerable people aka hypochondriacs forcing us all to join their personal dramas as spear carriers¹.
¹ A term for a usually mute background actor. No idea how common it actually is.
It may well exist – quite a few people say they felt differently to how they had done with other colds/flu. I can’t say whether that’s true or not for me as, being a hypochondriac, I have to ignore thoughts of this kind lest they escalate into serious illness. I think it’s plausible that people say it’s different because they’ve been told it is – but I suppose I would be accusing you of “imagining things” which would be rude and probably you’re not the “imagining things” type.
Spear carriers – like that.
Covid = a scam, a con.
Flying viruses don’t exist.
And you are right. The stupider you are, the greater the chance you will catch Rona. Your IQ did not change. It has remained <70.
Indeed, particularly if you have been vaccinated against it and variants come along.
Are you sure that decline in IQ isn’t the cause rather than the consequence. You have got to be really stupid to believe in all the Covid rubbish and to keep “testing” yourself.
Almost no IQ level is high enough to dominate the willingness of most people to conform to societal norms. What distinguishes us is principally that we are low on the extraversion and agreeableness traits, not that we are extra smart (in the sense of being able to do well on an IQ test, which is all that high IQ means). One could say that being low on agreeableness, we are more likely to value objective truth than those who are high on that score.
It is of course known that individuals with very high levels of IQ are also a bit autistic and can’t pick up on social cues.The high IQ doesn’t leave room for the brain to do other things well. That’s not quite the same as what most of us have.
The world needs more disagreeable people – this “be kind” thing is dragging us down. I’m talking about fake kindness, not true kindness.
Thanks. Now I have an excuse 🙂
I know some people who were never satisfied with a negative test and tested themselves repeatedly until,they got the ‘right’ result.
“Oh look, this positive test means an extra fortnight off work!”
“Show me an incentive and I will show you the outcome”. 🙂
So that explains why we have a Labour government!
“Even individuals who’d had an asymptomatic infection…”
No symptoms = no disease. So how did they know they were infected?
Testing. Yes.. low IQ.
Individuals with symptoms longer than 12 weeks – yes low IQ. Fantasy. Nobody has a Cold for 12 weeks.
A cold for 12 weeks, no I don’t think so either, but a flu perhaps will. I had a friend who once had nagging wife flu, I asked, “how do you know it is nagging wife flu”, he said that it was simple, it just seems to go on, and on, and on, and on…………
I expect your cancellation will be in the post.
‘nagging wife flu’ nice one
similar to ‘cackling hag syndrome’….
See also BMJ Opinion July 5 2021 “Time to assume that health research is fraudulent until proven otherwise?”
In case it helps: https://blogs.bmj.com/bmj/2021/07/05/time-to-assume-that-health-research-is-fraudulent-until-proved-otherwise/
Science is about stuff which can be measured. This means it’s about stuff which causes a physical effect in some measurement apparatus which is independent of conscious self of the people conducting the experiments. Consequently, anything related to IQ is not science as intelligence cannot cause physical effects indepdent of the people doing a so-called intelligence test. For instance, it’s impossible to tell if someone got a low score because he was too stupid to answer the questions correctly or because he was smart enough to ensure that his answers would almost always be wrong and felt like doing that for some reason. Carl mentions a study with a large sample size. This large sample size was really 9600 people. That’s 0.00288% of the number of people living in the USA or 0.00128% of the population of Europe or 0.00012% of the population of the world. Such a large sample size must obviously have covered all possible variants of everything! Considering both, the headline should probably be more something like Anecdotical evidence collected from a vanishingly small number of people does not support the theory that COVID affects people’s performance in so-called intelligence tests. Whatever that’s supposed to mean in… Read more »
It doesn’t affect your intelligence aside from a bit of brain fog. But it can affect your will and spirit in that if you feel physically sub-par for a prolonged perioid this can lead to a diminution in happy feeling. And the fact that you can’t exercise means that you don’t get the endorphins and other goodies associated with that. It definitely results in debilitation and our actions have ensured that it will not follow the normal pattern of evolution and become weaker. This bioweapon hasn’t even got started yet.