wringing the changes

Why does English r have such a strong labial component?

Despite Gimson’s claim in his Pronunciation of English, retained by Cruttenden (p. 220 in the seventh edition, 2008), that

The lip position is determined largely by that of the following vowel

nevertheless I am sure that I am not alone in lip-rounding initial r in read and rest just as in root and raw.

I have found that I can often improve English speakers’ pronunciation of Spanish or Italian r by getting them to get rid of the lip-rounding of this consonant that they wrongly carry over from English to the target language.

Where does this labiality come from?

Rohan Dharwadkar asks

Does the secondary labialisation of the RP R have anything to do with the loss of the labio-velar approximant in initial 'wr' sequences in words like 'write', 'wring', etc.?
My impression is that the R-labialisation is a relatively recent change, whereas the 'w's in question have been silent for a lot longer. And yet, for R to take on labialisation with no apparent trigger seems whimsical (which I realise languages very often are, but still.).

It’s an attractive idea, and one that I think has been floating around for some time, though I can’t put my hand on any discussion of it in the literature.

The OED, under the letter W, has a long discussion of “The combination wr”. Here’s a fragment.

Signs of the dropping of the w begin to appear about the middle of the 15th cent. in such spellings as ringe for wring v., rong for wrong adj.; these become common in the 16th cent. (for examples see wrangle n., wrap n., wreak n., wreck n.1, wrench n.1, wrest n.1, etc.). Reduction of the sound is also indicated by the converse practice of writing wr- for r-, which similarly appears in the 15th cent. (in wrath for rathe), and becomes common in the 16th; for examples see the subordinate entries under wrack n.1, wracked adj., wrap n., wretchless adj., etc. In standard English the w was finally dropped in the 17th century.

Pairs such as wring – ring, write – right, wrap – rap are homophonous in all kinds of modern English. Yet until a few hundred years ago they were distinct, the first in each pair having a labialvelar component and the second lacking it. Is it plausible that as the distinction disappeared it was the labialvelarized variant that became generalized, so giving us our modern labialized r?

Some idiosyncratic speakers take matters further. Gimson/Cruttenden again (p. 221):

some speakers labialize /r/ whatever the following vowel. In extreme cases, lip-rounding is accompanied by no articulation of the forward part of the tongue, so that /r/ is replaced by /w/ and homophones of the type wed, red are produced. Alternatively a labiodental approximant [ʋ] may be heard as a realization of /r/ or even for both /r/ and /w/. Pronounciations [sic] of this sort were a fashionable affectation in the nineteenth and early twentieth century; and can still be heard as such from some elderly people educated at major public schools.

I don’t know what evidence there is for accusing those who do this of a ‘fashionable affectation’. None, I suspect.

The Guardian’s parliamentary sketch writer Simon Hoggart regularly lampoons Sir Peter Tapsell MP for his supposed use of /w/ for /r/. Here he is recently.

Sir Peter Tapsell had made one of his stupendous interventions, calling for "the complete sepawation" (Sir Peter has a slight speech impediment) of commercial and investment banks.

I doubt very much that Sir Peter actually confuses /r/ and /w/. He does use [ʋ] for /r/, though. Listen here and judge for yourself.