How is IQ caluated at the lower ends of the scale?

Factual Questions
41

Kelby, yes, many were on those kind of test. But I never could find out right answers to use for the next test? I ended up guessing by system, in other words if there are 2 or 3 the same pick the largest one, like above “Sky” is the biggest blue thing—problem is how does one ever find out which one they DID want?

In the examples on the test there was ALWAYS just one correct answer and 3 or 4 bad answers I’d never pick. On the test there would almost always be 2 or 3 correct answers that fit, so do you pick the largest one as “Better” or what? And just who decides what is the best answer anyway? I think a true test would involve writing a sentence or two to explain the choice, and not having multiple right answers and someones opinion. Then the persons actual logic could be seen and judged. A better way could be that the answers would have explanations and then you’d pick the one with the clearest too, there are many ways to improve that kind of a test.

Getting back to memory testing, I think a memory test is fine too as long as the results are then reported as memory ability and not intelligence ability.

42

Well, with the kinds of items I think you are referring to, the examples are pretty straightforward, then they difficulty increases to the point where most people cannot figure out the relationship between the terms. The vast majority of people miss the higher level items on most subtests.

While there are some direct measures of memory (usually short-term) on ability tests, they make up only a fraction of the content.

43

qazwart writes:

> Officially, an IQ of 40 means a 10 year old child has a mental age of 4.

No, it doesn’t. That’s using the old quotient definition of I.Q. In the new standard deviation of I.Q., an I.Q. of 40 means that someone is expected to be (approximately) the lowest in intelligence in a random group of about 31,000.

electronbee writes:

> Hasn’t everyone in the US been tested in elementary school?

If I was, they didn’t tell me the score. I think that my school may have given everyone an I.Q. test at some point but they didn’t let anyone, not student, teacher, or parent, look at the scores unless the school decided that the student was having problems and it was important to figure out what was causing it.

Diogenes the Cynic writes:

> I don’t claim to have “scored” over 160.

I didn’t say that you claimed to have scored over 160. I wrote:

> Anyone who claims to have scored more than 160 since 1960 has been
> scammed.

Anyone means any random person, not you. If I had meant you, I would have said so. Clearly you made no such claim. Lots of people on the Internet claim to have bizarrely high I.Q. scores. They’ve been scammed (or are just lying).

Diogenes the Cynic also writes:

> Not exactly sure what point you’re trying to make here, but it wasn’t the only
> thing my parents were relying on, and my schools were willing to do it without
> any testing at all.

I didn’t say that it was the only thing your parents relied on. I wrote:

> Since far more than one person in 31,000 skips a grade (I would guess that at
> least one person in 200 skips a grade), if one relied purely on the test to tell if
> one should skip a grade that would say that you could skip a grade.

At no point in that did I mention your parents. I was talking about some random person. I said that if one relied on nothing but the test result, a score of 160 would have certainly be sufficient. I didn’t say that someone should or ever has relied on nothing but the test score.

In general, it’s a bad idea to try to figure out extrapolations of what I write. I write just what I want to say, and I don’t intend to imply things beyond that.

44

Agreed, but it would “help” with the retesters, specially in cases like Von Savant, who not only got retested repeatedly but trained in between. Retesting without knowing which results did you get right and which wrong would not be affected by memory, but if you’ve been given that information (and specially if you’ve been told the right answer), then hell yeah.

45

Maybe - when my wife had to take an aptitude test for a job interview, we googled various tests ahead of time. If you are used to this sort of stuff, or do puzzles a lot for fun, then it might be valid. but she’d been out of school for 15 years and this was the first such test she’d done.

We found some of those black/white/grey triangle/square/circle sequence puzzles. Once she saw a few and got the idea of exactly what they were asking for, it was easy. If someone threw that at you cold, it might be a bit more of an adjustment. The “aha” moment - “Oh, the sequence is a combination of the shape, shade, … I get it.” Similarly, she hadn’t done numerical sequence or other math puzzles either, so seeing a few and working through them made a big difference. For math, once you show the concept - they could be regular, 1-3-5; or the differences regular; it could be geometrical progression or squares or repeating patterns… How numerically literate are you?

Funny, a couple of the problems were almost identical to what she found online. So in the end, I’m sure she did a lot better than if she’d seen the test cold; particularly because it removed the confusion factor and enhanced her confidence.

So to a limited extent it helps; but you can’t seriously fake being smart.

46

The checklists that measure adaptive living skills give a breakdown of skills and their age equivalents. So there might be a category like “self-care” listing skills such as bathing, brushing teeth, dressing, combing hair, etc. Then each skill is broken down further- for example with dressing: putting on clothes, being able to fasten clothes, tie shoes, etc. Each skill has an age at which it should be mastered. Usually, it’s a broad range. If you can zip your own clothing, you are equivalent to an individual >5 years old. If you can’t, you are equivalent to <5 years old. Looking at the average age range of all skills, one can get a pretty good idea of where the person’s functioning level is. Frequently, individuals do have highly scattered skills (especially individuals with autism, who frequently have “splinter skills” which they perform very well). This is why I think it’s generally not useful to say, “Oh, he has the mind of a five-year-old.” Even if an adult has the cognitive abilities of a five-year-old, that doesn’t mean that they are emotionally five, with the same interests and concerns as a kindergartener.

Someone has already addressed your other questions, but no, IQ does not equate with mental age. It is more like a bell curve.

47

Having both worked with children who were mildly to moderately retarded and known a few people with IQs in the 140-150 range fairly well, I’d say no. While the low IQ child inevitably struggles due to their limitations, many people with IQs that high aren’t functioning at their full potential, so they’re far closer to a typical person in most ways that count than the other is.

48

Kind of OT but I do think that it’s sad that we have MR criminals. Some of them may be Fetal Alchohol Syndrome/severe ADD/MR combo…but others may have fallen through the cracks in terms of receiving social services.

49

To those who have answered here knowing about IQ: My impression was that the kind of intelligence that a high IQ measured was the ability to see patterns quicker than normal people. Or is this a misconception of Hollywood? Because that (and not photographic memory) is what a lot of “genius” people often seem to display - they say “But don’t you see that ------?” to an ordinary person, who only does after explantions.

I’ve also heard that originally, the IQ tests started out as a way to measure the developmental age and rate of progress for retarded children and was not intended to apply to normal children or adults. The idea was to test children who acted strange and find out whether they were developing normally; were faster and thus goofing off; or were slower and needed special coaching.

However, as John Holt pointed out in one of his books, a lower IQ thus only means that a child learns at a lower rate, not that he is principally impossible to learn something. He relates this together with watching a fellow teacher give a math lesson to severely retarded children - IQ of 40 or 50 - by using the wooden blocks (each length is a different colour). The teacher shows how the 6 block + 3 block make 9, then removes the 3 block and asks the children to find the missing piece. When they have, he removes the 6 block and asks for the missing piece. With normal 5th graders, a couple of repetitions would clue them into the principle. With these retarded children, they needed more than half a dozen repetions, but then, the lightbulb also went on. Once they got that idea, they moved toward 4+5 being nine, and they were quicker this time around.
Holt tells how he was moved by this demonstration of superb teaching and successful learning from the pupils, and their own joy at experiencing success.

50

Have you heard of the Flynn effect? It is the phenomenon of increasing test scores. Average scores in IQ tests are constantly increasing, so the tests have to be made more difficult or the scoring re-normalised.

A theory has been advanced that IQ tests really measure “scientific” or “categorical” intelligence. And our increasing scores are simply a measure of the changing way we apply our minds (after all; there’s no evidence of any change in our neurophysiology).
No cite, sorry, I think I read it in the economist.

I know how you feel. Right now I’m back at uni, as a mature student, and I still can’t get my head down, and study…
And I’m still not really into mathematical / geometric puzzles, even though I’m quite good at them. Whenever I’m working on such puzzles, I always try to “cheat”; because I find the puzzle too dull to do the “right” way.

Are you sure that’s how it works?
Say I give a test to 100 people. I get a neat normal distribution of scores around a mean of 40%, with a standard deviation of 5%.
Then someone comes along who scores 82%.
Now, it could be that my initial sample was not representative. Or, I could have encountered an “outlier”. But it seems weird to conclude “I haven’t got enough results yet, so I’ll call this score 50%”, say.
But IANA statistician…

51

I don’t know about that. I bet there are lots of things that a profoundly retarded person could never learn to do at a normal level, no matter how much he was coached.

I find this interesting - someone with the ability to commit murder who can’t tie his own shoes and sucks at playing hide-and-seek.

Regards,
Shodan

52

There’s no doubt about it. Folks in the lower 80’s have problems with abstract thought. Look at the commentators on Fox News, for example.

People that score below 60, for sure, are going to have a helleva time taking another person’s perspective on anything.

It is unfortunate that low functioning people are imprisoned when they may not have the capacity to appreciate what they have done. I would submit that this happens in only a very small percentage of cases, however. Most individuals who are very low are in a supervised environment for the most part after they turn 18.

53

While that’s true (a person with an I.Q. of 50 will probably never master multiplication, for instance), I think people generally underestimate mentally retarded individuals’ ability to learn. I started working a teenager with moderate mental retardation last year. Since then he has learned how to make simple meals, bathe himself, make his own bed, do his own laundry, and operate the TV and DVD player. No one had ever made an effort to teach him these things before because they assumed it would be pointless.

54

Well, I has a very, very high I;Q. My test said it was off the chart at 250mg/dl! I’ll never remember the time when my step-mother, step-father and me—all four of us—went in to get the test result from the proctiatrist and he was very excited about my high score—I was very proud. He did say, though, that it would go down if I limited my cholesterol intake (I’m not really sure what he was implicating they’re :confused:).

Apologies for the strained comedic interlude, but I do have a question: how well do the numbers correlate between the “old quotient definition” and the “modern standard deviation definition”?

55

Mijin, it’s the definition of I.Q. that makes it impossible for someone to have an I.Q. over about 200 or under about 0. In fact, it’s in practice impossible for someone to have a measured I.Q. over about 190 or under about 10, and in ordinary use it’s in fact impossible to have an I.Q. over 160 or under 40. What happens when a I.Q. test is devised is that it’s given to a large amount of people. The test is scored and all the results are then plotted on a normal curve, using 100 as the mean and 15 as the standard deviation. A score of 200 (six and two-thirds standard deviations above the mean) or a score of 0 (six and two-thirds standard deviatiations below the meas) could only be given as an I.Q. if you could say that someone has gotten the highest score or lowest score, respectively, among a group of about 100 billion people. Given that there hasn’t been quite 100 billion people in the entire history of humanity, that’s not possible. A score of 190 (six standard deviations above) or a score of 10 (six standard deviations below) would only be possible if someone was the highest or lowest score in a group of about 100 million. No I.Q. test has ever simultaneously been given to that many people. In fact, usually an I.Q. test is never given to more than about 100,000 people, so it can only be used to give scores between 40 and 160 (a range of four standard deviations above to four standard deviations below). If this doesn’t make sense to you, read the Wikipedia entries on standard deviations and on intelligence testing.

56

That’s a very good explanation.

Incidently, there was a question about the IQ’s of past president’s in this week’s Parade magazine. They reported that few scores were available, but did state that JFK’s was measured to be 119 and Nixon’s 143!

57

Ah. I knew 100 was defined to be the average score, but didn’t know much about the scoring system beyond that.

…

I’m pretty pleased to discover that I scored almost the highest that the Cattell B IQ test can measure :cool:

58

btw, I notice that a lot of celebs are often attributed surprisingly-high IQs.
e.g. Sylvester Stallone, 160; Sharon Stone, 154; James Woods, 180.

These usually turn out to be via online tests (one thing which sucks is that to join mensa, ordinary mortals must do a supervised test, but celebs can get in via online testing alone).
Aside all the other reasons to doubt these figures, would I be right in understanding it would mean that many of the most intelligent people on the american continent are all working as actors in hollywood?

59

Aren’t a lot of IQ scores calculated via the SAT tests that many Americans take, and where the scores can be looked up? Unless each US school in each state does really test each 4th grader with an official IQ test, and then release this confidential data to the Press, I don’t see how they get the scores for Presidents. But then, the US has a very different attitude towards data protection.

60

Whatever one thinks of his policies or his duplicity, Nixon was certainly no intellectual midget. He was first in his class at Whittier, then third at Duke Law. Supposedly he financed his first political campaign with poker winnings from his time as a WWII naval officer, which I have no trouble at all believing.