Gender only 'small factor' in boys' failure
But gender-differences make only a small contribution to the yawning developmental gap.
This summer's A-level and GCSE results have triggered a new round of debate over boys' underachievement.
However, the Birmingham research provides a timely reminder that other factors, such as poverty, ethnicity and season of birth, can have a far greater impact on a child's educational progress.
The statistical analysis has revealed that the most disadvantaged pupils are boys from a poor, ethnic-minority background who were born in the summer, never went to nursery and spent their primary years moving fom school to school.
By the age of seven, such children are, on average, more than two years behind more socially-
advantaged, winter-born, female classmates.
Education officers examined the cumulative effects of gender, poverty and race by comparing the 1996 baseline assessments of 11,250 four-year-olds with their performance in key stage 1 tests last year.
They found that, on average, boys were two months behind girls at the age of four, and that this gap widened to four months by the time they were seven.
The other disadvantages that put some seven-year-olds much further behind were: summer-born (an extra seven months), poor enough to qualify for free school meals (six months), and a Bengali or Pushtu-speaking background (six months).