CATs score in top schools

That's interesting Expat. You could well be right about the average IQ in London being a touch higher than 100, and that the average IQ of those who are in the market for private schools higher still. But, what we don't know is the standard deviations of these means - particularly the latter. It's possible that it's not even normally distributed in that population. I'm not a statistician (although know the basics) but I suspect that makes it really difficult to guesstimate how many will score over, say, 135 in the way that you have. I'm prepared to be corrected though.

@PickledOnion99

Your estimates of the number of boys with scores exceeding 125 assumes that the mean is 100. That's unlikely to be true in London and especially among the boys whose families can afford independent schooling.

While there is a great deal of debate about whether the cause is genetic or environmental, the evidence is quite strong that there is a positive correlation between family socioeconomic status and measured IQ. The average income in London is considerably higher than in the UK as a whole so I'd expect that the mean IQ of all children in London is higher than 100, perhaps something like 103. This is a small difference in the mean, but it is enough to increase the number of children with high scores by about 50%, i.e., expecting more like 3600 boys than 2400 boys with scores over 125, or 800 boys rather than 500 boys with scores over 135.

On top of that the families that can afford to pay for independent schooling are clearly better off than the London average. I'd expect that the mean IQ of children from the 20% or so of London families which can afford to pay for independent schooling would be higher than the London mean, perhaps something like 108. That would imply that there could be something like 1300 boys with scores over 125 and 350 boys with scores over 135 just from families who could afford to pay for independent schooling.

I regard Westminster and SPGS as the most academically selective schools for boys and girls in London. They have approximately 120 and 110 children each year in secondary, respectively. So, in theory, they could select with a minimum score of 135. I don't happen to believe they do this, if only because I am under the impression that the results of the pre-tests are not the primary selection criterion at these schools. However, I do believe it is possible the mean scores at these schools could be 135. And I also believe that anyone whose academic achievement is consistent with a score much less than 125 is likely to have a hard time keeping up at these schools.

Yes, sorry FlumePlume, I didn't make it clear that the 500 places referred to the combined Year 7 capacity of the handful of top schools.

It's also likely that some of the wealthier very high achievers in London will be leaving the city for boarding schools (I bet Eton and Winchester have tons of Londoners), again reducing the pool competing for day school places. I'm guessing that the obverse is rarely true (large numbers of children commuting from outside London to St Pauls etc)

However, it occurs to me that there is another flaw in my argument, and that is tutoring. Does this raise CATS scores? If so, then the proportion of kids achieving high CATS in Year 6 may be artificially elevated.

I would still argue that these school are unlikely to be looking for any more than a raw untutored CAT score of 125ish.

Sorry, ignore me, typing on the train and missed that you were saying 500 for all the schools.

pickledonion99 You are way out on the numbers in Y7. I think most of those schools will be nearer 100 than 500 in a year. Certainly the one I know (SPGS) is around 110 places at Y7.

I don't know what the scores are but agree about 120 or 125 may be more usual. I certainly remember who was at North London Collegiate school which will often beat some of the schools mentioned above for A level grades etc and is certainly on a par said there was even there a range of girls - some who were clearly genius level at everything and others middle or bottom of the class - even there the range of abilities exists - albeit everyone probably has the traditional UK grammar school level of about 120.

Our view was have a go. We put them in (in terms of sitting the entrance test) for the most academic schools at 5 on the basis that might be easier than getting in at 11 (or 13 for boys) when all the state school pupils pile in. Eg daughter 1 got into Habs but not daughter 2, at 5. Daughter 2 got into North London at 7 (in those days NL did not have a 5+ entry). They by the way each tried for the other's school just to see at 11+ and neither got into the other's for some reason but were happy where they were to age 18.

There was a chance the Habs one would not get into her seniors so she sat for about 6 schools at 11+ including Habs but got in anyway so no problem but it did illustrate that lots of people are trying for lots of schools. Also if there are quite a few you would like and can explain that to the child then the whole thing is just a bit of fun. It is when the parents make it feel really important that children get a bit stressed over it.

I'm not in London, but this thread has fascinated me.

Coming at this from a different angle, I don't think the scores required for entry to even the most demanding London schools can be as high as suggested in some posts here.

If we just think about the single-sex boys schools, for simplicity:

My back of envelope calculations suggests that there are around 100,000 11 year olds in Greater London. So, approx 50,000 boys. Let's assume that they all sit for St Pauls, Westminster, LU etc. If the CAT score required for entry was 135, fewer than 1% would be granted entry. So, around 500 would make the grade. I don't know these schools, but I'm guessing tht 500 would just about fill their Year 7 entry. BUT, we have made a huge assumption here - namely that every 11 year old boy sits for entry. This has to be way off. Even in London, only about 15% of kids are privately educated. And whilst it is possible that there is a socio-economic gradient on CAT scores, I refuse to believe that all of our 500 high fliers are in families that can a) physically get to, b) afford and c) want these schools for their kids.

Even if we stretch our criteria to a CAT score of 125, this only increases our potential pool to 2500 boys. Once you have removed those who live out in the 'burbs, can't afford, don't want one of these elite schools...how many will be left...?

Just my 2p.

My youngest came back with skewed CAT results which was odd. I questioned how she found the lower scored exam. She said it was fine but she didn’t finish because she spent ages fixing her wobbly table and then ran out of tissues to blow her nose as they had been used on the table. And she was at the back of the hall so couldn’t get the attention of anyone so she had to take them out one by one. Which tells me how bad her nose was cos she hates a wobbly table. Bless.

120 was the traditional 11 plus / gramamr school and the university entrance level (with people above but not many below).

I have been scanning as part of my current exercise of old family records and last week did the 5 chidren's various tests/assessments including this kind of thing. I think it's a mixture of gense and environment and some chidlren develop at different times. My child with the best A levels of my 5 children (he is now at university ) only did pretty well at sixth form level.

I cannot remember which bits of their tests I am remembering here but some of them had exceptionally high verbal skills, words, spelling when younger and their report 5 years late said it was really interesting how that hugely academic house full of books, reading, music, fun had had such a big impact on their scores 5 years below (5 years later they were I will do what I want teenagers and that bi of the score was lower than hit had been but still above average - they were at - those older 3 Haberdashers, North london Collegiate, Merhcant Taylors. And of those 3 2 are London lawyers and 1 drives a van.

My father was a psychiatrist and his colleague wanted someone to test on so I have still a copy my own tests at about age 8 too and ones I did later at about 20 (may be for me peak brain power) which was hugely higher.

Westbourne is correct.

The research shows that environmental factors can keep you well below your genetic threshold. Identical twins that are separated and raised in very different socio-economic circumstances have significantly more variation in their IQs than those raised in the same environment.

IQ doesn’t stabilise until later in life and in early life test results are heavily influenced by environmental factors including family birth order, education, economics, stress, nutrition etc etc.

The point is CAT scores for 10 year olds absolutely will improve with training in abstract problem solving tasks.

I think there is an individual threshold for everyone, child or adult. Environment can and does impact scores up to that person’s individual threshold. Beyond that threshold increased practice / positive environmental factors won’t have have an impact. What sets each person’s individual threshold is largely threshold is the genetic part. I have witnessed with my own DS how his scores increased with practice for 11+. But I suspect his scores will more or less plateau at some point.

Based on my children’s scores, I would have said it was largely genetic. My youngest has always had very high scores across all batteries, from a very young age, and are consistent year on year. Has had EP assessment which also correlates with these high scores. My other dc had lower scores with greater disparity between VR and NVR, and their respective traits were obvious from a very young age. Youngest was an innate problem solver, with an amazing ability to spatially recognise patterns and shapes and was able to complete 100 piece jigsaws at 18 months. Other dc was not interested in the same things at all, and they both had the same environmental exposure.

@Cos1ma

Both IQ and CAT scores are impacted by environmental factors like education. This is particularly true in children in which variation in IQ is up to 50 percent environmental.

Education and repeated exposure to abstract problem solving have repeatedly been proven to improve IQ scores. Google the Flynt effect to see how this works on a population level. Spatial reasoning is also very much a learned skill and scores can be improved right through adulthood with training.

I’m only clarifying as I think it’s quite dangerous to think about IQ as fixed and 100 percent genetically based as your post incorrectly suggests.

According to DS' prep these were the averages of the CAT scores of their boys who won places at the schools mentioned last year:
Eton 132, winchester 132, City 133, KCS 135, St Pauls 137, Westminster 137.

Our daughter’s CAT scores for year 3 to 6, have had overall mean between 137 and 139 with mainly 141s on quantitative, NVR & spatial. She has never been ‘prepped’ for these tests, and quite frankly we wouldn’t know how!
The average at our prep is around 105 to 110, depending on the year. However, I did hear of slight increases for kids who were being prepped for 11plus.

(a) There is not much in it
(b) All of these schools are excellent, but some are quite different from others
(c) All these schools send boys and girls to Oxbridge (to take one criteria), although some send more than others. It follows that choosing the best school for your child is more important than choosing the schools with the highest CAT score.

I understand these are about right:

St Paul's/St Paul's Girls/Wycombe Abbey 130
Eton/Winchester/CLSB/KCS/CLSG/Godolphin & Latymer/Latymer Upper/Cheltenham Ladies/Ascot 125
Harrow/Putney High/Francis Holland SS +RP/Downe/Calne/Dulwich/JAGS 120

expat - all I remember was, they had a list of schools and SPGS had 135 next to it. LU had 130, but they crossed this out and said it was more like 132 these days as it’s getting very popular. I think G&L was similar to LU. I didn’t really focus on Westminster because she’s a girl and also the school not a 13 plus prep.

There were various scores for DD over the years in columns. I was surprised her maths CATS were a few points higher than the ones relating to literacy as it’s the complete opposite in the classroom She’s always been an avid reader etc, but doesn’t really enjoy maths. So that just shows how the CATS don’t necessarily translate or reflect in actual performance. They said she could get into SPGS on a good day. They said G&L was something of an unknown quantity as the exam has changed, but plenty of girls with similar profiles have gone there. They said LU was more unpredictable due to the huge numbers that sit and also they put more emphasis on the interview there, it’s not just about test scores. They said PHS should be fine and also another school. She got into all the schools except LU where she didn’t get an interview. She didn’t want to go to SPGS for her own reasons.

I think a given child will do equally well at any of these schools tbh and the differences are wafer thin. It’s more about their personality, the atmosphere and the friends. I couldn’t care less which school gets 99% 7/8/9 and which gets 93% - as long as your child is happy they’ll do what they’re going to do. Mental health in teens is a massive issue which I have sadly witnessed in friends of my older DC, one or two of whom have dropped out of LU for these reasons and only scraped four or five GCSEs at 5s and 6s.

@Cos1ma

SPGS, SPS, G&L, LU & Westminster - you need to be 132 plus on average.

Are you sure that you interpreted the numbers correctly? The straightforward parsing of what you wrote implies that every student would need a minimum of 132 on the average of their four CATS scores to get a place at these schools. Is it possible that the headteacher meant that the average CATS scores of all the students at these schools is 132? Which would imply that some students could get places with somewhat lower scores.

I had grouped a few schools together that I was told were in the 130-135 category, if you can call it that.

With all due respect to the headteacher that gave you the names in that category, it's hard to believe there's not more separation between SPGS & Westminster, and G&LS & LU, given the differences in the results.

Expat - I will pm you why I believe that to be true.

I have no idea why you’re getting so aggro about this cake.

First of all, I did NOT say LU requires scores of 135. That was for SPGS.

I had grouped a few schools together that I was told were in the 130-135 category, if you can call it that.

Specifically on LU, when my son applied 5 or 6 years ago, they said it was around 130. It is apparently harder for boys to get in because there are fewer boys options in the area, so maybe this only applied to boys. This last year when DD applied, they said it had crept up to more like 132 because numbers are increasing g every year.

As needmoresleep explains, this does NOT mean you have to be 132 in everything, but that you have some scores in this area - maybe in the more key areas that matter to the schools.

My DS has speed processing issues for instance. He was in the 18th centile for this when he was assessed as a younger child. He was assessed before GCSE and he had improved yet was still on the 83rd centile for this.

The prep schools are just going on children who have received offers at certain schools over many years and being honest about the kind of profiles of those that get in. They are not trying to put anyone off applying. That makes no sense. It’s in their interests to get as many children in to as many schools as possible.

I totally agree LU dies take children with “spikier” profiles than other school perhaps. I actually think this is one if their strengths. For instance, a few super-duper mathematicians in DS’ year were the ones who came out with a “6” in English, for instance. There are quite a few DC with dyslexia or aspergers, etc at LU and it’s not seen as a barrier, just a different learning style. They are often particularly strong in certain areas.

Again, CAT tests are not the same as the other termly standardised tests schools do, in which the 125 that you quote would be very high.

Going back to what you say in the beginning about “120 and you’re in”, well , this is simply not true. Any child can have a bad day. DD has CAT scores of 141 in maths - she didn’t get into LU. I was waiting outside with the mum another child who also had those CATs in some areas, she didn’t get in either. This happens all the time. But they all tend to get in somewhere.

@cakeisalwaystheanswer

I found the (separate) blog post to which you seem to be referring. The estimate of 125 they make comes from a highly dubious methodology. Which other studies link back to this? I'd like to see those.

So an average IQ of 125 is fine for Cambridge apparently but nowhere near good enough for Latymer Upper which then does pose the question of why so few from Latymer actually get into Cambridge?

Perhaps 1) because the correlation between academic ability, academic achievement and what Cambridge are looking for is not perfect, and 2) because a lot can happen in the 7 years between 11 and 18.

Please note, I'm not disputing your conclusion that the idea that Latymer Upper requires a minimum of 135 CATS is false. I'm questioning the arguments you're using to support your conclusion.

My own guess (based on quite limited data) is that, at SPGS or Westminster, above 130 you're a good candidate and you should certainly be able to keep up if you get a place, 125 you can have a go, below 120 you might find it difficult to keep up even if you got a place. G&LS and LU, I would have guessed 5 points lower, i.e., that above 125 you're a good candidate, 120 have a go, below 115 you might find it hard to keep up.

Based on the estimates you posted earlier, I don't think our conclusions are actually very different.

expat - the blog I linked to also shows the detailed study made of Cambridge undergrads which shows them to have an average IQ of 125, this is considered the standard and all other studies link back to this. The reason I mentioned Harvard is because it illustrates how the uplift that practising for these tests provides skews these results and suggests that the student IQ has shot up in recent years when this isn't the case. So we'll stay with Cambridge because it's in the UK and everyone here understands the entrance process and it sets the standard for IQ tests. So an average IQ of 125 is fine for Cambridge apparently but nowhere near good enough for Latymer Upper which then does pose the question of why so few from Latymer actually get into Cambridge? I do apologise for Latymer parents for singling this school out but 135+ is just ridiculous.

I have seen the charts for one of the top London Indy schools that my eldest attended with better results than Latymer. The average was well below 135 and the bottom figures a very long way down. These charts were factual, based on an actual year groups tests not pie in the sky theories.

If people want to believe that writing a cheque to a prep school adds 20 points to a childs IQ so be it (although that did drop to 15 in a few posts). And if I were to believe the posts on MN I would believe the average CAT score of their DCs to be between 130-140 so maybe joining MN adds 30-40 points to your child's IQ, it's just as likely.

I would happily leave people to spout nonsense on MN if it didn't put parents like Westbourne off applying to schools.

@Cos1ma

The way I understand it, it’s imposdible to “prep” for CAT tests.

Yes and no. As with almost any test, being familiar with the format and timing increases the scores, on average. So doing a few practice tests will help most pupils. However, in theory, further practice beyond that shouldn't change the expected scores. I don't know how true that is. After all the "tutor-proof" 11+ turned out not to do what it said on the tin.

@cakeisalwaystheanswer

still you insist that the inate average ability of a SW London Indy pupil is higher than that of a Cambridge or Harvard undergrad.

The blog post you linked earlier only provided estimates for Harvard, not Cambridge, so I'll address that one. Yes, it is entirely possible that average pupil at a top SW London independent school has higher academic ability than the average Harvard undergraduate. And I speak as someone with experience of both systems.

First, you have to understand that Harvard and top SW London indies have very different incentives. A top SW London indy's raison d'etre is to get its pupils to the next level of academic education, i.e., university. They would be lauded if 100% of their students were to get places at Oxbridge. Hence, when they select pupils, they select first and foremost on academic achievement, which is strongly positively correlated with academic ability.

Believe it or not, Harvard's main purpose is not to get its pupils to the next level of academic education. Harvard does not want 100% of its graduates to go to academic graduate programs and then become professors. Harvard wants its graduates to achieve in a wide range of fields and so selects on the basis of achievement in a wide range of fields, only one of which is academics.

On top of that, Harvard were recently sued for discrimination in their admissions practices. Some of the documents exposed in the lawsuit revealed that over 40% of their undergraduates were admitted on the basis of some sort of preference, whether legacy (children of alumni), athletic, Dean's List (children of large donors), or affirmative action (disadvantaged minorities). The documents also demonstrated that these students had significantly lower academic achievement than the rest of the student body who, as I noted above, already were not selected principally based on their academic ability.

I'll even go further than my initial comment. I don't believe it's just possible that the average student at SPGS or Westminster has higher academic ability than the average student at Harvard, I believe it's quite likely.