So the scientists concluded, this is a polymorphism, different phenotypes existing in the same population. Some people’s digestive tracks produce the malodorous compounds, and some don’t. Simple enough right? I’ve been told they even managed to find the corresponding genotypes, and the correlation they had was great. I heard it got as far as children’s textbooks, before someone pointed out a tiny flaw in the experiment.

The experimenters had been a bit shy in their work. They’d fed people asparagus and asked: “Now does your pee smell?” when they should have asked the more risque: “Does his pee smell?” Had they asked the latter they would have found that ≈40% of people said yes all the time, and  ≈60% said no all the time. Because it turns out that everyone digests asparagus the same way and outputs the same urine, it’s just that not everyone can smell it.

…transforms my chamber-pot into a flask of perfume -Marcel Proust

This post was inspired by an old Daniel Miessler post which surfaced yesterday on Hacker News entitled “ Why Planes Fly: What They Taught You In School Was Wrong .”