In a report published this week, the Equal Opportunities Commission said that while girls regularly outperform boys in English and literacy at key stage 2, there is no gender gap in maths and science at the same level.
By contrast, British pupils who received free school meals scored 22 per cent lower in their KS2 English tests than those who did not. Boys who do not receive free meals regularly outperform girls who do.
The Roehampton University researchers who compiled the report claim that social class is therefore a larger factor than gender in determining educational achievement.
Steve Sinnott, general secretary of the National Union of Teachers, is unsurprised. "Children whose parents didn't have a good time at school tend to see it as a hardship," he said. "It's very difficult to show them that it's an enjoyable experience, where you develop, make friends and do new things."
The Roehampton researchers said that gender differences should not be disregarded. They claimed that such stereotypes are self-perpetuating, often bolstered by school ethos and expectations.
Peer pressure establishes appropriate behaviour for girls and boys. Laddish behaviour, along with a reluctance to work hard, are seen as masculine traits.
The researchers said: "Girls and boys may be drawn to different subject areas due to their own ideas of what is appropriate for their gender. Their choices may therefore reflect the desire of individuals to align themselves with apparently gender-appropriate subjects."
But attempts to tackle gender imbalance by catering to boys' and girls' different learning styles are often counter-productive. The report said: "Teaching practice based on gender builds on stereotypes and can exacerbate differences."
The researchers believe teachers should not make assumptions based on sex, ethnicity or social class, but instead view pupils as nuanced individuals with individual ways of learning.
The schools that succeed in raising the achievement of any one group are those who expect high achievement from all pupils, regardless of gender or background.
The report said: "Schools should be encouraging diversification of skills and interests to broaden horizons and thus improve the life chances of girls and boys."
But Trefor Lloyd, director of the educational charity Working with Men, argued that when schools cater specifically for Afro-Caribbean boys, all pupils do well.
"Assuming that all boys should be stuck in front of a computer or made to rush around in PE is crass," he said. "But we can't go to the other extreme, and say that nothing gender-specific works. It's a complex business."