Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.
Showing posts with label immunology. Show all posts
Showing posts with label immunology. Show all posts

Thursday, September 16, 2021

Bias amplification

Last week I had a frustrating exchange with an acquaintance over the safety of the COVID-19 vaccine.

He'd posted on social media a meme with the gist that there'd been so much waffling and we're-not-sure-ing by the medical establishment that you couldn't trust anything they said.  I guess he'd seen me post something just a few minutes earlier and knew I was online, because shortly afterward he DMd me.

"I've been waiting for you to jump in with your two cents' worth," he said.

I guess I was in a pissy mood -- and to be honest, anti-vaxx stuff does that to me anyhow.  I know about a dozen people who've contracted COVID, two of whom died of it (both members of my graduating class in high school), and in my opinion any potential side-effects from the vaccine are insignificant compared to ending your life on a ventilator.

"Why bother?" I snapped at him.  "Nothing I say to you is going to make the slightest bit of difference.  It's a waste of time arguing."

He started in on how "he'd done his research" and "just wasn't convinced it was safe" and "the medical establishment gets rich off keeping people sick."  I snarled, "Thanks for making my point" and exited the conversation.


It's kind of maddening to be told "I've done my research" by someone who not only has never set foot in a scientific laboratory, but hasn't even bothered to read peer-reviewed papers on the topic.  Sorry, scrolling through Google, YouTube, and Reddit -- and watching Fox News -- is not research.

Unlike a lot of anti-science stances, this one is costing lives.  Every single day I see news stories about people who have become grievously ill with COVID, and whose relatives tell tearful stories after they died about how much they regretted not getting the vaccine.  Today's installment -- from a man in Tennessee who has been in the hospital for three weeks and is still on oxygen -- "They told us not to worry, that it was just a bad cold.  They lied."

The problem is -- like my acquaintance's stubbornly self-confident "I've done my research" comment -- fighting this is a Sisyphean task.  If you think I'm exaggerating, check out the paper that came out this week in Journal of the European Economic Association, about some (actual, peer-reviewed) research showing that not only do we tend to gloss over evidence contradicting our preferred beliefs, when we then share those beliefs with others, our certainty we're right increases whether or not the people we're talking to agree with us.

The phenomenon, which has been called bias amplification, is like confirmation bias on steroids.  "This experiment supports a lot of popular suspicions about why biased beliefs might be getting worse in the age of the internet," said Ryan Oprea, who co-authored the study.  "We now get a lot of information from social media and we don't know much about the quality of the information we're getting.  As a result, we're often forced to decide for ourselves how accurate various opinions and sources of information are and how much stock to put in them.  Our results suggest that people resolve this quandary by assigning credibility to sources that are telling us what we'd like to hear and this can make biases due to motivated reasoning a lot worse over time."

I don't even begin to know how to combat this.  The problem is, most laypeople (and I very much include myself in this) lack the expertise to comprehend a lot of peer-reviewed research on immunology, which is usually filled with technical jargon and abstruse details of biochemistry.  And every step you take away from the actual research -- from university or research-lab press releases, to summaries in popular science magazines, to blurbs in ordinary media, to Some Guy's blog -- introduces more opinions, oversimplifications, and outright misinformation.

And I'm completely aware that Skeptophilia is also Some Guy's blog.  I will say in my own defense, however, that I do try to base what I write on the actual research, not on Tucker Carlson quoting Nicki Minaj's tweets about how her boyfriend got the COVID vaccine and afterward his balls swelled up.  (No, I am not making this up.)

So that's today's rather discouraging scientific study.  It's sad that so many of us have to become gravely ill, or watch someone we love die in agony, before we'll admit that we might have been wrong.  I'll just end with what the research -- from the scientists themselves -- has to say: the COVID vaccines are safe and effective, and the vast majority of people who have had severe COVID are unvaccinated.  The "breakthrough cases" of vaccinated people testing positive almost never result in hospitalization, and when they do, it's because of comorbidities.

But don't take my word for it.  If you honestly want to know what the research says, and you're willing to keep an open mind on the topic and shape your opinion based upon the evidence, start here.  And after that, go out and get the fucking vaccine.

Seriously.

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London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]


Thursday, January 9, 2020

Lying down with dogs

We love our dogs, but there are times when we look straight into their big brown eyes and say, "You are the reason we can't have nice things."

Of course, given that neither of our dogs are known for their excessive brain power, they usually respond by wagging cheerfully.


Sometimes I think our dogs are not so much pets as a pair of home demolition experts.  Both of them track mud everywhere, a problem made worse by Guinness's love of swimming in our pond.


There's also the issue that when he chases his tennis ball -- his all-time favorite occupation, one that he is capable of doing for hours on end -- he performs his catches with all the grace and subtlety of a baseball player sliding into home.  The result is that he has torn our back lawn into a wasteland of rutted dirt, which in early spring when the snow melts turns into a giant mud puddle.  We've been renovating our walk-out basement, and while considering what flooring to put in, I suggested that we simply spread an enormous plastic tarp on the floor and call it good.

Carol felt that this didn't set the right aesthetic for our home, and I suppose she's right,  but it would certainly be easier to keep clean.

And it'd be nice if tracking dirt everywhere was all they did.  Guinness (code name: El Destructo) has a great love of chewing stuff, and despite having approximately 1,485 chew toys, he is constantly finding stuff to tear up that isn't technically his.  So far, we've lost shoes, slippers, books, paintbrushes, pieces of unopened mail, a set of iPod headphones, and so many cardboard boxes that I've lost count.  He's also an accomplished counter surfer, and just a couple of weeks ago he snagged a half-pound of expensive French brie, something we still haven't quite forgiven him for.

I guess I didn't realize that when we picked him out at the shelter, we were on the Bad Doggie Aisle.  That'll teach me not to read the signs more carefully.

Anyhow, when we ask our dogs, "So, what good are you two, anyway?", they don't generally have any answer unless you count cheerful wagging.  But maybe they will now -- because two papers, one in the Journal of Pediatric Allergy and Immunology and the other in PLOS-One, have shown that dogs actually do have a positive contribution to make (above and beyond companionship), especially to the health of children.

In the first, "Early Exposure to Cats, Dogs and Farm Animals and the Risk of Childhood Asthma and Allergy," by a team led by Vincent Ojwang of Tampere University (Finland), we find that children living with dogs and/or cats when they're very young have a statistically significant lower chance of allergies, asthma, and eczema than children who don't.  The mechanism is poorly understood -- it may have something to do with early exposure to dirt and pet dander desensitizing children to harmless antigens -- but the effect was clear.  The sample size was nearly four thousand, so it's not an inconsequential result.  (Interestingly, the correlation with farm animals was uncertain, perhaps because farm animals aren't in the home and exposure to them is not only more limited, it's more likely to occur in the open air where concentrations of dust and dander are lower.)

The second, "Exposure to Household Pet Cats and Dogs in Childhood and Risk of Subsequent Diagnosis of Schizophrenia or Bipolar Disorder," by a team led by Robert Yolken of Johns Hopkins, found that (even when you control for other factors), a child who lived with a pet dog for a significant amount of time before age thirteen was 24% less likely to be diagnosed later with schizophrenia.  (There was no similar correlation with cat ownership; the reason is unclear.)

As with the allergy/asthma study, the mechanism behind this correlation is uncertain.  "Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life, and since household pets are often among the first things with which children have close contact, it was logical for us to explore the possibilities of a connection between the two," Yolken said in an interview with Science Daily.  "Previous studies have identified early life exposures to pet cats and dogs as environmental factors that may alter the immune system through various means, including allergic responses, contact with zoonotic bacteria and viruses, changes in a home's microbiome, and pet-induced stress reduction effects on human brain chemistry...  [Some researchers] suspect that this immune modulation may alter the risk of developing psychiatric disorders to which a person is genetically or otherwise predisposed."

So I suppose I must grudgingly admit that our dogs actually might serve some purpose other than getting hair all over the sofa, barking at the UPS guy, and chasing away terrifying intruders like chipmunks.  Maybe we should credit their dirt-spreading capacity with the fact that our sons are both completely healthy and allergy-free.  At this point, though, since Carol and I are both clearly adults, they can lay off changing our home's microbiome.  I'll accept the risk of developing an allergy if I don't have to put up with Lena lying down next to me after having rolled in a rancid squirrel carcass.

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This week's Skeptophilia book of the week is simultaneously one of the most dismal books I've ever read, and one of the funniest; Tom Phillips's wonderful Humans: A Brief History of How We Fucked It All Up.

I picked up a copy of it at the wonderful book store The Strand when I was in Manhattan last week, and finished it in three days flat (and I'm not a fast reader).  To illustrate why, here's a quick passage that'll give you a flavor of it:
Humans see patterns in the world, we can communicate this to other humans and we have the capacity to imagine futures that don't yet exist: how if we just changed this thing, then that thing would happen, and the world would be a slightly better place. 
The only trouble is... well, we're not terribly good at any of those things.  Any honest assessment of humanity's previous performance on those fronts reads like a particularly brutal annual review from a boss who hates you.  We imagine patterns where they don't exist.  Our communication skills are, uh, sometimes lacking.  And we have an extraordinarily poor track record of failing to realize that changing this thing will also lead to the other thing, and that even worse thing, and oh God no now this thing is happening how do we stop it.
Phillips's clear-eyed look at our own unfortunate history is kept from sinking under its own weight by a sparkling wit, calling our foibles into humorous focus but simultaneously sounding the call that "Okay, guys, it's time to pay attention."  Stupidity, they say, consists of doing the same thing over and over and expecting different results; Phillips's wonderful book points out how crucial that realization is -- and how we need to get up off our asses and, for god's sake, do something.

And you -- and everyone else -- should start by reading this book.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]