Bad reasoning

A recent NYT article provides an almost textbook example of how bad reasoning can fuel conspiracy theories. The author claims to provide five pieces of evidence suggesting that Covid escaped from a lab in Wuhan, China. In fact, none of the pieces of evidence are at all persuasive, and some are factually inaccurate. Here I’ll focus on the first piece of evidence cited, the inferences that we should draw from the fact that Covid happened in Wuhan.

The article shows a graph of the “hundreds of large cities” within about 1500 miles of the bat caves where Covid is thought to have originated:

Then we are led to believe that it would be an amazing coincidence if Covid were to naturally emerge in the one city in this region that just happened to have a major virology lab.  But is this claim true?

In 1994, I got married in Beijing.  Our honeymoon was spent in Wuhan and Chongqing.  Is it an “amazing coincidence” that my honeymoon was spent in the city where Covid originated?  As we will see, the answer is no.

A more pertinent example occurred in 2014, when virologist Eddie Holmes visited the animal market in Wuhan where Covid first spilled over to humans.  He snapped a picture of a cage with a raccoon dog, and speculated that this is the sort of place where a future pandemic might emerge:

What’s even weirder — it turns out that one of the co-authors of the study, Eddie Holmes, had been taken to the Huanan market several years before the pandemic and shown raccoon dogs in one of the stalls. He was told, “This is the kind of place that has the ingredients for cross-species transmission of dangerous pathogens.”

So he clicks photos of the raccoon dogs. In one photo, the raccoon dogs are in a cage stacked on top of a cage with some birds in it.

And at the end of our sleuth work, we checked the GPS coordinates on his camera, and we find that he took the photo at the same stall, where five samples tested positive for SARS-CoV-2.

I don’t know about you, but that seems like an even more major coincidence than the virus emerging in Wuhan.

The NYT article is wrong; Wuhan is not just one of hundreds of large cities, it’s a Chinese megacity.  Southern China has four megacities (Wuhan, Chongqing, Chengdu, and Guangzhou/Shenzhen), or five if you view Guangzhou and Shenzhen as separate metro areas.  They are all hundreds of miles from the so-called “bat caves”.  Pandemics are far more likely to emerge in these places than in the hundreds of other Chinese cities.  These cities have many affluent shoppers, and huge animal markets that attract exotic species from all over China.  Also dense populations and lots of visitors from elsewhere.  Places that are magnets for people and trade.

But let’s say I am wrong, and that there is nothing special about these four Chinese megacities.  In that case, the lab leak proponents face another problem.  Unlike with Covid (aka SARS-2), there is absolutely no dispute about how SARS-1 crossed over into humans back in 2002.  It first showed up near a wild animal market in the Guangzhou metropolis.  So people who reject my claim that southern Chinese megacities are special have merely traded one amazing coincidence for another.  Now they have to explain why Covid emerged in the giant city of Guangzhou, and not one of hundreds of other southern Chinese cities.  

Here are the facts:

SARS-1 is known to have crossed over in an animal market that was roughly 900 miles from the bat caves.  There were intermediate animal hosts.

SARS-2 first showed up in people that worked and shopped in an animal market about 1000 miles from the bat caves.  The famous virology lab was in a completely different part of the giant metro area.

Please apply Occam’s razor.

Most Americans have very limited knowledge of Chinese geography, and are therefore easily persuaded by the sort of argument provided in the NYT.  So consider an American analogy.  Imagine a pandemic emerges among people who work and shop near an animal market in Flushing, a Chinese area of NYC.  Pandemics are known to have previously begun in such markets.  Then someone on the internet points out that the pandemic began in “New York City”, which also happens to contain a hugely important virology lab at Columbia University.  Maybe there was a lab leak, and the infected scientist just happened to go way across town to do some shopping at an animal market in Flushing, thereby infecting other people. 

Does that seem like a very plausible “conspiracy theory”?

Throughout history, many global pandemics have begun in southern China.  Even by Chinese standards, the southern Chinese are famous for eating a wide variety of exotic animals.  Southern China has a dense population, often living in close proximity to animal life.

Yes, the NYT article also contains other “evidence”, all of which is equally weak.  Those other points have been refuted here and here and here.