Super monster, you’re right, it does depend on the child. Your 4 year old may be ready but the majority are not and this affects them long into their school life. And yes, sociallly it’s relevant too, it’s not just academics, it’s feeling like the smallest, the least able, the one who finds things more difficult. It’s nothing to do with ability, it’s simply that developmentally the difference between 4 and 5 is massive, and the closer you are to 5, the easier you find it. The converse of that is that the closer you are to 4, the more difficult you may find it. There are exceptions, I know a summer born who was no different to their peers, though I know many many more who struggled. I also know autumn babies who don’t shine academically or socially, but again, many many more who do. Not innately brighter or more confident, just bigger and better when compared against th spectrum of your average class.
What happens now is quite different academically. The Tory governments have pushed acihievement right down, so what you are expected to achieve now in reception was previously a benchmark expected in years 1 or in some cases even year 2. When I was at school, the reception or nursery year was exactly that, and you learned to read and write proper in year 1. That’s not the case now, so the ever increasing pressure put on schools to deliver on results is necessarily pushed onto the kids, some of whom are just not ready, and the majority of thOse not ready will be summer born.
The problem is with academic expectstiokns, and front loading education, and how this makes these tiny people feel about education. If your first year of school life is spent struggling to do even the smallest of tasks, your confidence and attitude to learning can be permanently damaged.