Is this actually true? It's one of those bits of "telephone wisdom" I've heard passed from commenter to commenter on Hacker News (and Slashdot before that) for

Is this actually true? It's one of those bits of "telephone wisdom" I've heard passed from commenter to commenter on Hacker News (and Slashdot before that) for as long as I can remember, but nobody ever seems to have a primary source for it, it's always been a "just trust me" bit of knowledge.