The brilliant -- and not so brilliant -- schoolboy

I enjoyed Ed Cook's post on Ralph on The Brilliant Schoolboy, following on from a comment made by Jim Davila on Paleojudaica.

There is another side to the archetypal "schoolboy", though, the one who makes basic errors of reasoning. B. C. Butler, The Originality of St Matthew. A Critique of the Two Document Hypothesis (Cambridge: Cambridge University Press, 1951): 63, criticises previous synoptic scholars for making "a schoolboyish error of elementary reasoning at the very base of the Two Document Hypothesis". I wondered if this "schoolboyish error" phrase might itself be a motif in academic writing of a certain era (when male scholars in male universities were looking back on their days at boys' public schools), but was surprised to find only Butler's use above coming up when I googled for it.