In a sneaky attempt to build up traffic to the other blog I'm working on as part of my new job, here's a cross-posting. A week or two back, the research of Dr Ewa Dubrowska from Northumbria University was reported on in a couple of places, and since then there's been some discussion about what her research proves or doesn't prove. The gist of her work is that some people who have not gained higher level qualifications (gone to university, in other words) find it harder to understand some grammatical structures than those who have those qualifications.
While some might argue that this just proves that some people are smarter than others, it's not quite that simple. Pretty much everyone picks up grammar very quickly as a child, even though we are not taught it explicitly when we are young (or ever, in some cases). Some have argued that her research shows that we don't all have a common grammatical understanding: that the built-in grammar we are told is part of our genetic heritage by the nativist theorists such as Noam Chomsky and Steven Pinker isn't as developed as we have been led to believe.
Others have argued that it raises no such doubts and all Dabrowska's research tells us is that some people are better at taking tests than others. Anyway, there's more here on the Teaching English Grammar in Schools blog, including a link to BBC i-player where you can hear a fairly clear introduction to the debate on the Material World programme broadcast last week (20 minutes into the programme).