In the previous post, I did this thing that I give my students BAD GRADES for doing, which is: assume that something is “scientifically proven” without doing my own research.  These common adages are so tempting, especially when people on the internet are constantly saying things like, “Since it’s scientifically proven, or something, that __________.”  I pulled out that old saying, “every cell in the body is replaced every seven years,” and Josh, my internet conscience, has blown the internet whistle.  Apparently there ARE cells that don’t replace themselves: neurons.  I kind of knew this, but it was hiding in another part of my brain that I don’t usually draw on while writing blogs.  More’s the pity.

But yes—ok—is it more or less reassuring that neurons have been with us since the womb and could potentially outlast us, according to a “science writer” at Phenomena, National Geographic’s online science salon ?  I was pretty obsessed, for a couple of days, with the idea that not even our memories—the patterns of impulses that store and replay them, the cells that carry and transmit them—are as old as we are.  That we ourselves are not even as old as we are.  Goes off like a bomb in the brain!  But now I am reminded that our brains, for the most part, have been our companions throughout childhood and are still with us.  I think that’s reassuring.  Not even people suffering from dementias are hosting strange new brain cells—some of their old cells are simply moving on, picking up coats and jackets, and leaving.

I feel especially dumb, since I just wrote a review of a book on eugenics in the early twentieth-century—a “scientifically proven” set of principles that reached common-sense status (and white-supremacist-sense status, and Nazi-sense status) before it all came crashing down.  History of science, I guess.

So, here’s a bit of errata, which—really—the internet should be full of.  I’m glad to do my bit.