Have you heard the phrase “irrational antagonism”? Roach implies it’s a technical term from psychology for “what happens between people isolated together for more than about six weeks”1. As an introvert I think I reach that stage in more like six hours, but anyway, the fact that there’s a scientific term for it may be my favorite thing I learned from this book. (Admittedly several of the top Google results for “irrational antagonism” are just other reviews of this book, so perhaps it’s not really a widely used term.)

“Irrational antagonism” is also my cat’s philosophy of life. And a good band name. And the official motto of [insert political party here].

I listened to this as an audiobook, and I zoned out a lot, but pretty much any time I tuned in it was talking about something interesting, such as:

Vomit is a more dangerous material to inhale than, say, pond water. As little as a quarter of a mouthful can cause significant damage. The stomach acid that is a routine ingredient in vomit will handily digest the lining of the lungs.2

Bodily fluids, odors, etc do take up rather a lot of the book, which might be a reason to avoid the audio version—I found myself listening to a story about a free-floating turd right as I was biting into some baked ziti. But the gross stuff is fascinating. Who knew that one of the scientific frontiers pushed forward by the space race was the question of what happens if you stop taking baths?

Soviet space biologist V. N. Chernigovsky, in 1969, carried out a restricted-bathing experiment of his own, this one including bacteria colony counts. The bacteria populations in subjects’ armpits and groins plateaued somewhere between the second and third weeks. At which point there were roughly three times as many colonies as on freshly washed skin. (Except on the feet and buttocks, where there were seven to twelve times as many.) A Navy study turned up similar findings; here some subjects’ bacteria counts even began to drop after two weeks.3

That chapter included this surprising claim:

Most Americans don’t wash often enough to cause skin problems, but they certainly wash more than necessary. In the words of some academic I can’t name because I’ve lost the first page of his paper, “Personal hygiene as practiced in the U.S. today is largely a cultural fetish, actively promoted by those with commercial interests.”4

Anyway, this book amply reinforces two opinions I already held: