Grammar Schools

In the UK, up until the 1970's, we had both what are called Grammar schools and Secondary Modern schools that children attended from the ages of 11-16 years old.  Those who passed a test called the 11+ attended the Grammar schools, the rest attended the Secondary Modern schools.  I believe it was only around 20-25% of children went to Grammar school.  

From the following article, the author Allison Pearson says:

I’m spitting mad. For 40 years, since the 1976 Education Act compelled local authorities to introduce comprehensive education, we have had to put up with the nonsense that grammar schools are evil and that a kid like Adam will do as well in an average comp as a child in a select pool of motivated high achievers. Well, he won’t. Far too often, such a child will drown. For four shameful decades, our country has sunk down the international education league tables, social mobility has stalled and hundreds of thousands of our brightest children have been betrayed.

...

By contrast, if you’re a brainy British kid who could seriously do with being plucked from their background, selection is a dirty word.

By "brainy" I assume she means intelligent.  Although intelligence might be a pre-requisite for passing the test, it'll obviously involve more than that.  A child who rarely listens in class or/and who has no interest in school and the knowledge it can impart (myself for example) will be highly unlikely to pass such a test, no matter how intelligent they are.    

But I agree with the author that an intelligent child won't generally do as well in a secondary modern. Indeed, I think that most people will agree that grammar schools are better in terms of instilling an education.  Presumably very few think of them as being "evil".  The problem is that their existence necessitates the existence of secondary modern schools, which will be worse than comprehensives (no selection at 11 years old, I attended such a Comprehensive school).

Another issue is that I doubt that one's education actually increases one's intelligence, at least not in one's innate capacity to understand various issues.

Note I'm not saying I'm opposed to grammar schools -- I don't know whether I am or not. But to simply focus on how great grammar schools are and ignore how poor secondary modern schools were, is not to provide an impartial view.