The proportion of male to female heads varies widely from region to region - with women making huge inroads in London and other urban areas. The latest research by Kay Fuller, a lecturer in English education at Birmingham University, has found that women outnumber men in six London boroughs including gritty areas such as Newham, Lewisham and Camden. In seven other boroughs, the proportions are equal.
The list of high-profile and highly paid heads in the capital is long, from Jacqueline Valin at Southfields Community College in Wandsworth to Jo Shuter at Quintin Kynaston School in north London. While in Knowsley, a particularly deprived area of Merseyside, seven out of nine heads are female; women also outnumber men in Oldham and Stockport.
Figures from Education Data Surveys - a sister company of The TES - show that of primaries appointing a new head last year, only 13 per cent of London schools chose a man, compared to 46 per cent in the South West and 44 per cent in Wales. And the Future Leaders programme, which prepares teachers for tricky urban headships, was 70 per cent women in its first intake four years ago, suggesting a "heroism" among women determined to work with the most deprived.
But Professor John Howson suggests these figures may reflect the difficulty of recruiting to schools with more complex challenges, rather than illustrating a forward-looking feminist outlook in urban areas.
"Fewer apply for headship in difficult urban areas so governors are less likely to find someone for the post," he says. "We believe many female heads were reluctant deputies persuaded to act up. These women were coerced into the job at first, then realise they can do a good job and apply for it."
In other words, women are picking up the tricky jobs that men don't want. "There is also the issue of fewer graduate opportunities in places like Wales and the North East, so men are more likely to go for top jobs in education," he adds.
But Ms Fuller, who is examining the national picture in detail, says although she suspects an "inherent conservatism" in rural areas, more study is needed.
"You have pockets where heads are more likely to be women, but it doesn't always follow that urbanisation means more female heads" she says. In rural Denbighshire, North Wales, she adds, six out of eight heads are women, yet none of Peterborough's heads are.
"It will be interesting to see what these authorities are doing differently, or whether women in those areas are better supported by their husbands," she says. "It's complex and unlikely to be due to one thing."