The Sun once again fails to understand the rules of causation.
They are implying that having a 'posh name' enables you to do better at GCSE.
Whereas I reckon that people whose genes and/or upbringing pre-destines them for academic success are more likely to have been given sensible, non-chavvy names!
When I was about fourteen I read a book that gave characteristics of certain names. I was told that my name characterised self-confidence, independence, and academic success. So I resolved to become that person, and I think, by and large, I did.