It's good to have a man or four about the place
It has become a common assumption that male teachers are beneficial to boys' education. Government recruitment drives have focused on the importance of male role models, particularly in primary.
But Mr Ashton, one of four male teachers at Montem primary, in the inner London borough of Islington, struggles to define what he offers that female teachers cannot.
And he is not alone. Several academic studies, including a 2005 Durham University project examining almost 9,000 pupils, found no link between achievement and the sex of the teacher. Only one study, in the US in 2006, concluded that pupils achieved better results with a teacher of their own sex.
As a result, Becky Francis, professor of education at Roehampton University, questions the wisdom of government policy. "Just because someone is male, you can't expect they will adopt a particularly masculine approach," she says. "There's immense diversity between men teachers, just as with any teachers. They're individuals. They have different teaching styles.
"It's ridiculous to expect, just because someone is male, that they will relate to, or teach, pupils in a particular way." This is borne out at Montem. Down the hall from Mr Ashton's classroom is Year 4 teacher Chris Evans. The two men have little in common: Mr Ashton is married with children; Mr Evans is not. Mr Ashton is a laddish football fan; Mr Evans is quieter and less sporty.
Professor Francis says: "The kind of male teacher that policymakers envisage is never articulated. There are hints that they should perform a disciplinarian role. But people go into primary teaching because of their love of kids. That doesn't fit with the disciplinarian model."
Montem serves disadvantaged and immigrant pupils, many of whom come from single-parent families. Sue Seifert, its head, therefore believes it is vital that the school has male teachers. "Where would they get male role-models from otherwise?" she asks. "TV? Or computer games?"
Mr Ashton agrees. He suggests it may not be the specifics that matter, as much as the mere fact of his maleness. "I'm not saying I'm a great role model," he says. "But I'm not swearing, not slapping them about, not beating their mum. I'm just doing the right thing. And they don't see a lot of men like that."
Ironically, though, the most convincing argument for men in the classroom comes when Mr Evans talks about working with female pupils. "In some aspects of primary, we cater too much to the boys," he says. "Class stories are always neutral, or boys' stories with boy heroes. So I read books that the girls are quite into. I make the point to the boys: 'it's okay to like this'."
Professor Francis, like Mr Evans, believes that male teachers' most important role can be in breaking down boys' assumptions: wearing pink to school, or reading traditionally girl-oriented books.
"It's healthy if the teacher workforce reflects society," she says. "It opens up the possibility for kids to see teaching as a career.
"We have a wealth of talent of potential male teachers, which isn't being tapped because of the construction of nurturing professions as feminine."
Ms Siefert, similarly, believes that school staff should be drawn from across the community: "It's not about how macho male teachers are; it's about how sensitive they are. It's important for pupils to see that men can be caring, too."