Someone asked about studies on the effectivbeness/intake of grammar schools? I dont think there have been any since the 1960s/70's but going back there, one reason there was a push to remove them was that they were not found to be effective.
A big issue was ( like now) the num,ber of prep tutored DC who got in.
Another issue was that even though there was far less competition from independents ( many such schools started in the 1950's after the 11+ was made a general test at 11 for all DC and grammar schools stopped being pay - for institutions) parents were unhappy about the standardof education available to those who were "failed".
There was a discrepency across the country justlike now. In some areas ( Wales for example) a large proportion of DC went to grammar school In the Midlands - around Birmingham and the Black Country, the % was far lower. That was made worse by the fact more boys were admitted than girls and there were more boys grammar schools than girls high schools generally.
Yet still, even then, middle class parents dominated the entry. Only a few working class DC got in to start with.
Of those w/c DC many had middle class mothers or middle class maternal backgrounds ( grand parents and aunts etc).
Many w/c children may have gone to grammar school but a lower % actually did well academically. Compared to their m/c counterparts they got fewer O levels and many times failed the benchmark % O levels with English and Maths (to go onto sixth form).
It didnt increase greatly the numbers of such DC who went onto university ( universities only too 5% of the A levels any way and A level wasonly taken by 10% of all DC anyway).
So it was not the great leveller and social mobility ladder it has been made out to be. Yes a few did rise in the world through the system. Largely this was around one step up ( say from skilled working class to lower middle class occupation). So mobility was not great unlike the myththat it was.
I got this from an old book written in the lae 1960's " Home School and Wrok: A study in Originals and Cestinations" by Carter. I have a copy. It was obligatory reading for me once. Similarly a book called " Why Children Fail" by Holt, gave similar statistics although it concentrates more on the disadvantages of class in the education system generally.
Bernstein of course gave us the low down on why there was a discrepency - the middle class have an elaborated language code. This advantages them in any education system. Similarly in case you need to be told Bourdieu suggested it was "cultural capital" that made a difference. Letsliken the latter to your school bag. All DC come to school with their school bag. However, the contents of the school bag of a M/c child ( things like language, books, support, space at home, economic position etc) better fits them to do well in school than their w/c peers. This starts before school - by the age of 3 this has been set really.
There were also studies which showed that able DC would work fairly well in any school if they had ability.
I think there were a number of such studies in the 1960's/70's. Of course having abandoned 11+ in most areas further studies were not necessary.
So why do parents want to send their DC to Grammar school? I doubt its because of the riviting curriculum which in most cases can be found in any comprehensive since all schools do teach the same uniform curriculum.
It wont make much difference really.
Of course sending a DC independent means you get a different education most of the time as NC doesnt apply.