@Geamhradh
The educational dip comes not, as you might think, at the end of a long summer, but as you get towards it.
Which is slightly unfortunate when you think about where the exams are.
This is absolutely true. Children are all fired up and raring to go in September. By the end of every term and half-term they are dragging themselves along, tired.
Disadvantaged students would be better in camps / forest school / enrichment activities over summer, having structured days, reading and being regularly fed healthyish meals. But there is absolutely no need for all students to have reduced time off when they could be pursuing other interests. Not all children are disadvantaged. And also, by treating everyone the same, how does that level the playing field at all? Focus intervention where it is needed. Giving it to everyone does nothing but widen the gap.