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!]

Study shows readers of Skeptophilia have above-average intelligence!

One rather frustrating tendency, amongst those of us who have a skeptical bent, is that people tend to believe anything they read if it begins with "Study Proves" or "Research Shows."

Even better if it says "Harvard Researchers Show."

Apparently, it doesn't matter much whether the study actually proved the claim, or who the researchers were, or if the "Harvard research" was peer reviewed.  Merely claiming that some scientist, somewhere, of whatever credentials, said something -- well, that's enough.

Especially if what the scientist allegedly said fits in with what you already believed.

I ran across a particularly good example of this in Natural News, which I will not provide a link to because Mike "Health Ranger" Adams definitely doesn't need unsuspecting people generating any more clicks or ad revenue.  Least of all if they come from here, of all places.  The headline was "Study Shows Unvaccinated Children Are Healthier," and referenced a paper at Open Access Text called "Pilot Comparitive Study on the Health of Vaccinated and Unvaccinated 6- to 12-year-old U.S. Children," by Anthony R. Mawson, Brian D. Ray, Azad R. Bhuiyan, and Binu Jacob.  So I decided to check out the paper itself.  Here's a bit of it, so you can see their basic argument:

Vaccinations have prevented millions of infectious illnesses, hospitalizations and deaths among U.S. children, yet the long-term health outcomes of the vaccination schedule remain uncertain.  Studies have been recommended by the U.S. Institute of Medicine to address this question. This study aimed 1) to compare vaccinated and unvaccinated children on a broad range of health outcomes, and 2) to determine whether an association found between vaccination and neurodevelopmental disorders (NDD), if any, remained significant after adjustment for other measured factors.  A cross-sectional study of mothers of children educated at home was carried out in collaboration with homeschool organizations in four U.S. states: Florida, Louisiana, Mississippi and Oregon.  Mothers were asked to complete an anonymous online questionnaire on their 6- to 12-year-old biological children with respect to pregnancy-related factors, birth history, vaccinations, physician-diagnosed illnesses, medications used, and health services.  NDD, a derived diagnostic measure, was defined as having one or more of the following three closely-related diagnoses: a learning disability, Attention Deficient Hyperactivity Disorder, and Autism Spectrum Disorder.  A convenience sample of 666 children was obtained, of which 261 (39%) were unvaccinated.  The vaccinated were less likely than the unvaccinated to have been diagnosed with chickenpox and pertussis, but more likely to have been diagnosed with pneumonia, otitis media, allergies and NDD.  After adjustment, vaccination, male gender, and preterm birth remained significantly associated with NDD.  However, in a final adjusted model with interaction, vaccination but not preterm birth remained associated with NDD, while the interaction of preterm birth and vaccination was associated with a 6.6-fold increased odds of NDD (95% CI: 2.8, 15.5).  In conclusion, vaccinated homeschool children were found to have a higher rate of allergies and NDD than unvaccinated homeschool children.  While vaccination remained significantly associated with NDD after controlling for other factors, preterm birth coupled with vaccination was associated with an apparent synergistic increase in the odds of NDD.  Further research involving larger, independent samples and stronger research designs is needed to verify and understand these unexpected findings in order to optimize the impact of vaccines on children’s health.

Okay.  So, boiled down to its essence, (1) they admit that vaccines save lives, given that hardly anyone dies of diphtheria, polio, or tetanus anymore; (2) they claim that there seems to be an increased risk amongst vaccinated children of learning disability, autism spectrum disorder, ADHD, allergies, and asthma.

[image courtesy of the Wikimedia Commons]

Here's the problem, though.  Virtually all of the increased risks they describe are for conditions in which there is a huge spectrum of severity.  About 30% of adults and 40% of children are allergic to something, but these vary from sneezing during ragweed season to dying of anaphylactic shock if you consume a crumb of residue from a tree nut.  ADHD, in my experience as a teacher, ranges from kids who are a little fidgety to students who seem to be physiologically incapable of concentrating for more than five minutes on anything.

Hell, I have a learning disability in decoding written material myself; if I were in school today, I'd probably qualify for special services.  But I get along just fine, and in fact love to read even though I'm a bit slow at it and tire quickly.  I've had students, however, whose learning disabilities profoundly impacted their ability to manage most of the tasks they were expected to master in school.

So self-reported (or, in this case, mom-reported) conditions for which there is tremendous variability already makes the study a little questionable, especially given that those data are being compared to ones which are unequivocal -- such as whether the child in question ever got measles.

But there's a deeper problem still, and that is that the authors come into this question with an axe to grind.  As physician and blogger David Gorski points out over at his wonderful blog Respectful Insolence, the lead author of the study, Anthony Mawson, is an anti-vaxxer and had shopped around without success for a home for his paper in peer-reviewed journals, and finally had to post it at an open-access site because it couldn't pass review.  He did get an abstract accepted at Frontiers in Public Health -- but they retracted it only days after it was published, saying it was "under re-review."

Hardly a ringing endorsement.

Another problem is that homeschooled children are not a representative sample, nor are their parents.  There are lots of reasons for homeschooling -- one of my best friends homeschooled her daughter for the best of reasons, and she came out of the experience with a finely-honed mind and a deep passion for learning.  But there's a significant correlation between an homeschooling parent and being an anti-vaxxer, especially given the crackdown in many states on allowing belief-related exemptions for unvaccinated children to enter public school.

So right away there are some questions about the legitimacy of the data.  As I point out to my Critical Thinking students, sample bias doesn't mean the conclusion is wrong, necessarily, but it does cast it in a rather dubious light.

Last, and perhaps most damning, is the fact that Mawson's "study" was funded to the tune of $500,000 -- by an anti-vaxx group.  You'll note that nowhere in the paper cited above was any mention of a conflict of interest vis-à-vis financial support.

Which is a major no-no for a peer-reviewed study.

So mainly what the "Study Shows" is that if you walk in with your conclusion already in hand, you can bend the data whatever way you want to support it.  Especially if your pocketbook is being filled by people who would like very much for you to prove that their pet theory is right.

The bottom line: be careful when you see anything that claims that "Researchers Prove X."  Go to the source, and ask yourself some hard questions about the veracity of the study itself.  (Especially if you're inclined to believe its conclusions; confirmation bias plagues us all, and we're much more likely to accept something unquestioningly if it squares with what we already believed.)

And that goes double if it's Harvard researchers.