Essentially, Panchin et al. have noticed that some rituals spread germs. (They’ve mostly ignored the many, many cleansing rituals that seem to do the opposite). So, they ask, what if germs, looking to spread, drive people to perform rituals? This isn’t quite as outlandish as it sounds. Many germs really do alter their hosts’ behaviors in ways that help the germ spread (think of rabies, which spreads by biting, and which alters the brains of infected mammals to make them feel very, very aggressive; or consider Toxoplasmosis, a protist associated with cats, that seems to cause infected rats to feel less fear of felines).
Of course, the urge to bite your fellow mammals is, perhaps, a shade less nuanced than all the possible reasons that might motivate a person to take communion, or kiss an icon, or travel to Mecca and mingle with strangers.
Still, undeterred by their total lack of evidence, the paper’s authors proceed boldly into the realm of the hypothetical. They cite Star Wars, in which Jedis get their powers from weird blood-borne microbes, called midichlorians, as a good analogy for this idea of spirituality-emerging-from-germs. They talk about the unsanitary qualities of holy water. They wonder if religious fasts are intended to help clear out the gut so that certain fast-inducing microbes can move in and take up residence. “I thank the authors,” wrote one peer reviewer, “for think [sic] outrageous thoughts.”