Jeremy Wagstaff, who runs technology consultancy Loose Wire Organisation, says: "Americans speak loudly and clearly and are usually in a hurry, so it makes sense for them to have a female voice because it has the pitch and range. British people mumble and obey authority, so they need someone authoritative." Which, apparently, still means male.There's more historical context here (which talks about disembodied machine voices having been female for a long time, since telephone operators* and WW2-era navigation systems, female voices being used in railway station announcement systems because their higher frequencies carry better against the train noise, evil computers in films being presented as male, and BMW having to recall a female-voiced navigation system in the 1990s because of complaints from German men who refused to take direction from a woman).
There's also a piece in the Atlantic about why many electronic devices designed to assist have female voices. It looks predominantly at systems in the US, and concludes that, in America at least, female voices are perceived to go better with the role of assistant—competent, level-headed, and unthreateningly loyal. Or, in other words, everybody wants to be Don Draper.
Which doesn't answer the question of why (according to Apple's in-house cultural anthropologists, anyway) British users feel more comfortable with male-voiced virtual assistants. Could it be the lack of the famous 100-watt smiles of the American service industry (as per the US psychologist who categorised British smiles as grimaces of acquiescence)? An ingrained sense of social hierarchy and/or traditional acceptance of class privilege which makes authoritative male voices more acceptable in Britain? (I wonder whether refined-sounding male British voices would be popular with American users; after all, I imagine that quite a few people wouldn't mind their virtual assistant to have a British butler persona.) Or perhaps the residual trauma of Thatcherism makes female voices with any hint of authority a hard sell in Britain? And why does Australia get the female voice option by default? Is Australia more "American" than "British" in this sense? Or is the preference for male voices some peculiarly British anomaly among the English-speaking nations?
* If I recall correctly, the very first telephone operators in the late 19th century were boys, of the same background who would have been employed in clerical tasks. They tended to horse around and play pranks too much, though, so they were replaced with female operators after a few years. Throughout living memory, the typical telephone operator (where those still existed) has been a woman.
I don't have an iPhone 4S, but I understand that Apple does allow the user to choose, though presents them with a default set for their country.
Here's an experiment done in Britain on people's preference for gender of an automated voice. Men preferred a woman's voice but women had no preference for gender. People preferred an accent from their own region.
http://spotlight.ccir.ed.ac.uk/public_documents/technology_reports/No.3%20Voices.pdf
They should do an experiment with voices in lifts. Psychology returns to the elevator! http://www.guzer.com/videos/elevator-psychology.php
I'm inclined to agree with your butler theory. In the (former) land of butlers and batmen, a refined male voice politely responding to your commands suggests (the phone user has) status. Everywhere else, an assistant to a person with status is expected to be a female secretary.
Proof for me would be if non-British hipsters exhibited a preference for the British male voice.
What I don't get is why the gender and sexual persuasion of the user doesn't seem to influence their preference for phone-voice gender?
And why doesn't Apple just allow the users to choose?