I haven't read the whole thread yet, so apologies if I'm repeating PPs.
I have a DS and a DD.
When DD started at school, her teacher said that girls are ready to learn from the start of reception, whereas boys "want to roll around the floor and wrestle". She felt that boys should be allowed to expend their energy, rather than being made to sit at desks and work.
From the moment DS started school (different school), his teacher was determined to make him and the other boys "behave"; at the age of 5, he was put on a behaviour report for putting water in the same tray, and every positive behaviour mark was negated if he then got a negative. Lots of the boys got similar treatment, but it was virtually unheard of for any of the girls to be disciplined, even if they behaved in a similar way.
Likewise, a girl asking "why" was seen as curious, where a boy was seen as cheeky/rude/disrespectful.
When DS moved up to the only male teacher in primary school, that teacher would yell at the boys...but not the girls.
DS is nearly 14 now, and DD is 16.
DS is bright and able. He thrives when teachers don't try to squash him or insist he stays "inside the lines" - that doesn't mean he has to have his own way in class, just that he does better with teachers that engage with him, take an interest in what he has to say around a subject etc.
Luckily, he's at a school that is boy-heavy, with lots of quirky and inspiring teachers who know how to get the best out boys, whilst keeping a fair and steady hand on any behaviour issues. Consequently, DS is thriving and working hard.
DS and DD are so totally different in what motivates them; I know this is down to personality, in part, but I also think it's a gender thing and until schools recognise that one-size doesn't fit all, I can't see boy's achievement improving.
I also wonder if the highly prescriptive nature of GCSEs, with their rigid mark schemes, just doesn't suit boys in the way it might suit girls?