>Who calls it that? It comes from some studies[1] that show a large number of neurons in the gut which control subsystems, which number about as much as a cat

>Who calls it that? It comes from some studies[1] that show a large number of neurons in the gut which control subsystems, which number about as much as a cat brain. This is interesting and makes things more complicated than initially thought, but is a bit apples to oranges; just having as many neurons as a cat brain doesn't mean they operate like you hacked a brain into your gut. Spitballing here, but this probably started as an analogy to show the number of neurons, and people started thinking it was an actual brain. [1]https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-brain-gut-connection https://www.hopkinsmedicine.org/health/wellness-and-preventi... (Maybe not the best source, but google "human gut cat brain" and you'll see this view all over the place.)