I recently had a coworker mention that we might prefer selecting a handful of familiar fonts for some built-in themes for a software application we are developing over a handful of other potential font choices (for example, Georgia over ET Book, an open-source Bembo clone) because he recalled that he had read somewhere that familiar typefaces are easier to read than unfamiliar ones. Can anyone help source a reference for this assertion (or sources for the opposite idea, namely typical considerations of typeface legibility)?
Ignoring goofy, extreme, illegible or tasteless fonts (Comic Sans, Papyrus, Arial -- all problematic for their own sakes) on the familiar side as well as lousy, poor, crazy fonts on the unfamiliar side, my understanding is that font choice depends mostly on the use case itself (body v. title), the quality and readability of the font itself, how it is applied (font size, letter-spacing, line-spacing), document-wide consistency, etc.
Like I said, ignoring really weird fonts or poorly designed fonts, is there any reason to prefer broadly familiar ones over potentially better-designed, high-quality fonts? (I can't imagine a typographer ever uttering such a Familiar Implies Readable mantra, lest no one buy her fonts!)
Is there any other non-legal and non-technology-related reason (assume we have that licked -- we could ship and enable both TTFs or WOFFs as appropriate) to prefer a widely familiar font if other choices are available, all things being equal? The only thing I could come up with is that it might be a little distracting to be reading a new font (especially body copy), thus drawing a little attention to itself, or that the reader has already internalized a representation of familiar fonts in their visual cortex? (No sources for this, just applying some brainstorming.)