IQ tests

[Eos of the Eons]

Someone should do an IQ test (link to one) on a fundy site, then at a homeopath site, and then at some astrology/psychic site with a poll for everyone to choose the range in which they scored.

I've never gotten over 135 on any IQ test I've tried online. It's those questions with "banana, apple, orange, grapefruit" That screw me up. You're supposed to pick one, and I can never figure out wth.

Most people who take IQ tests for fun score over the average. What is the average anyway?

 

[wipeout]

Re: Re: Re: Re: Re: IQ tests

I agree wipeout, but the point people seem to be missing is that prediction significantly better than chance is a very useful thing

The .5 validity of an IQ test, means that-- more than any other single measure in existence-- if you had to use one thing to predict whether an applicant was qualified, your best bet would be the iq test (It will predict significantly better than chance, and as it turns out, sig better than any other single measure).

There will be cases where the qualified guy wasn't hired, and the non qualified guy was, but ironically, using the IQ test will minimize those cases.

Yeah, I understood you are obviously perfectly right about this, any extra filter of applicants will help, and an IQ test can be a good one. I'm not really against the tests, I think they should be better understood by anyone who choses to use them.

There are some important issues for job selection and IQ like different IQ scales giving different IQ numbers but the same meaning, or IQ scores too high for the test misleading people into thinking different numbers that high still have any predictive power.

Even Mensa have screwed up and are unwittingly selecting below their own entrance requirement because they think "IQ" on one test is perfectly equivalent to "IQ" on a different test and allow entrance on any of a number of tests.

Mensans really ain't as smart as they think they are.

Of course, what's else that could be going through a selector's mind is far more of a concern for fairness in job selection than IQ testing could ever be.

 

[wipeout]

Someone should do an IQ test (link to one) on a fundy site, then at a homeopath site, and then at some astrology/psychic site with a poll for everyone to choose the range in which they scored.

I've never gotten over 135 on any IQ test I've tried online. It's those questions with "banana, apple, orange, grapefruit" That screw me up. You're supposed to pick one, and I can never figure out wth.

Most people who take IQ tests for fun score over the average. What is the average anyway?

I think the "banana, apple, orange, grapefruit" ones can be pretty poor items on tests as people can find several things about them that are different but as right or wrong as another.

Three names end in a vowel. Grapefruit doesn't.
Three are round. A banana isn't.
Three don't grow in bunches. Banana's do.
Three names have no vowel repeated. Banana repeats one.

And so on...

Then the freaking answer turns out to be orange.

 

[Mercutio]

Then the freaking answer turns out to be orange.

Well, duh...of course.......orange is the only one that is a color. The rest are just fruit.

Some people are just so...

 

[bpesta22]

OK, then it isn't measuring intelligence, it's measuring success. Those are clearly not the same thing.

It's a measure of intelligence that is a valid predictor of job performance. In other words it has criterion validity predicting job performance.

It could be awkward writing on my part above, but I think you are talking about construct validity (which answers how we know IQ tests measure intelligence).

Convergent (test predicts things it should) and divergent valdity (test doesn't predict things it shouldn't-- for example, personality) establish the construct.

Read Jensen's latest book on g for a comprehensive account of the construct validity of IQ. The evidence for g is overwhelming!

And the importance of g is that it has criterion validity for just about every measure of success we have in life.

You can't say that a test for intelligence is accurate if it predicts success. You are talking about a test for success, then.In which jobs? How do you measure job performance?

Again, my crappy writing may have confused you-- it's the difference between criterion and construct valdity. IQ tests have both.

To the second part-- any job and and valid / reliable measure of job performance you can think of (output, sales, PA ratings).

So much validation data, such good science that the US court systems accepts their use in selection, even though they discriminate against minorities (i.e., why would SCOTUS ok a company to use an IQ test for selection when using one results in hiring far less minorities than you should have in a "fair" world????)

Just one example:

Schmidt, F., & Hunter, J. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124, 262-274.

It seems to me that you are using a very narrow definition of intelligence, that fits what you're trying to measure. Not intelligence, but something else. Or, at least, only one aspect of intelligence.

Lemme be clear: Intelligence is g. g is the first order factor extracted EVERY time you give a battery of cognitive abilities tests to a group of people.

g is general intelligence; it is probably some very basic mental process like speed of processing or working memory effeciency / capacity.

It shows large individual differences. Increases from birth to maturity, and declines in old age; has a very strong hereditary component and predicts everything important in life (tho imperfectly) often better than any other single predictor.

Your lawyer example

I concur completely, but you are looking at it the wrong way. I'd bet IQ is an incredibly crappy predictor of which grad students at Yale ace the program and which just barely pass.

But, get 100 people in a room, all 100 of them have an iq of 85.

Get 100 other people; all of them have and IQ of 115.

I'd bet Randi's million (and I bet he would bet it also) that at the group level the 115's would be far superior lawyers than the 85's.

In fact, the relationship between IQ and job performance is Non Linear: Having the minimum level of IQ for the job is critical (if you're a 100, you will never be a rocket scientist, no matter how hard you try).

But, if you have the min, having more than that doesn't help-- and may actually hurt -- job performance. I am arguing that you can be too smart for your job, but let's save that for another debate.

B

 

[Martin]

I am arguing that you can be too smart for your job, but let's save that for another debate

That explains why I can't find a job I'm any good at. Anyone know the minimum IQ requirement for, say, the post of Evil Genius?

 

[epepke]

what is their importance? Why are they around?

Assuming that you don't mind an actual serious response, IQ tests were designed for the purpose of identifying children who needed extra help with their studies or possibly some other method of teaching. As far as I am concerned, that is their strongest claim on validity.

 

[Michael Redman]

I agree that there's a mental quality that can be measured with IQ testing, I'll buy your assertion that they tend to end up more successful than those who score lower.

It still seems to me that you're talking about a very narrow section of mental ability which can readily be measured through these types of tests, and not the full range of mental ability which leads to success, happiness, or whatever it is our brains are for. The testing is biased toward a particular type of analytical thinking, and, while that might be usefull in some circumstances, it isn't a true measure of "intelligence" as that word is commonly understood.

 

[Wrath of the Swarm]

In fairness to Gould, he was really attacking the idea that IQ tests measure what we generally think of as "intelligence". Professional researchers have done a very poor job of educating the public about what IQ tests are and how they're useful.

 

[Paul C. Anagnostopoulos]

Pesta said:
A strong correlation indicates a reliable test (it'd be odd to flunk the even numbered items, yet ace the odd ones, if the test were indeed reliable).
...
Just wondering if anyone has read to this point

I have, teacher!

I understand how this would validate the reliability of the test. I still do not understand how you can jump to the conclusion that the test has anything to do with intelligence per se, except by defining intelligence to mean doing well on the test.

~~ Paul

 

[bpesta22]

I agree that there's a mental quality that can be measured with IQ testing, I'll buy your assertion that they tend to end up more successful than those who score lower.

It still seems to me that you're talking about a very narrow section of mental ability which can readily be measured through these types of tests, and not the full range of mental ability which leads to success, happiness, or whatever it is our brains are for. The testing is biased toward a particular type of analytical thinking, and, while that might be usefull in some circumstances, it isn't a true measure of "intelligence" as that word is commonly understood.

Hey Mike.

The problem with positing multiple types of intelligence is:

1) any other type of intelligence is also correlated with g.

2) with g in the iq test, the test predicts nearly everything. Take g out, and the test predicts nothing.

I certainly feel there are many ways to be smart-- book smarts, street smarts, common sense, creativity, etc. But, the only one that consistently predicts important life outcomes is g.

The problem is that no one has yet invented a specific cognitive abilities test (e.g., "the test of street smarts") that predicts many important things, but that doesn't also measure g.

It may seem like a narrow definition; a small subset of what people perceive intelligence to be, but it's consistently the only one that matters in the lit.

But in my world view, it makes sense. g is something very basic-- how fast the neurons in your brain fire, which determines how much info you can process at one time, which certainly lends itself to being smart (or not smart) in nearly any situation.

It's interesting to note that these tests of "information processing capacity" predict car accidents among the elderly better than actual, on-the-road driving tests!

I think my point in bragging about all the different things g correlates with is to illustrate that there really is one basic important type of IQ that matters / predicts (imperfectly) success in life in many different ways.

Think about it-- how fast you arrange blocks to form a picture predicts (though very weakly) which teenagers will become pregnant.

This amazes me.

 

[Wrath of the Swarm]

Reality check: 'g' is a hypothetical common factor postulated to explain the degree of correlation between many different measures of cognitive function. Don't put the cart before the horse.

 

[Michael Redman]

1) any other type of intelligence is also correlated with g.

I don't know if that's true. And how could you, if other types of intelligence can't be tested? I certainly suspect that some kinds of creative intelligence do not coincide with IQ test intelligence.

I certainly feel there are many ways to be smart-- book smarts, street smarts, common sense, creativity, etc. But, the only one that consistently predicts important life outcomes is g.

I have to wonder if "important life outcomes" for this analysis aren't selected measures that can be confirmed with the tests, and not what people might otherwise consider to be important life outcomes. And, even then, is IQ responsible for the good outcome, or are people set up for good outcomes also set up for good IQ scores?

 

[Wile E. Coyote]

I certainly feel there are many ways to be smart-- book smarts, street smarts, common sense, creativity, etc. But, the only one that consistently predicts important life outcomes is g.

I think that it is up to an individual to decide what outcomes in life are important. Success should be measured by personal happiness, not societal approval. A lot of high-IQ people are not happy.

I have a very intelligent friend who would not score well on IQ tests. He works well with tools and has a lot of common sense. He learns how to build and fix things quickly. He can add up measurements easily, but is not generally good at math.

This kind of intelligence is not measured by IQ tests, but it is very important to our society to have people with these abilities.

I can score high on nearly any IQ test, but I do not have the ability to reason like my friend.

For these reasons I find IQ tests to be insulting to a great many intelligent people.

 

[Michael Redman]

In fact, the relationship between IQ and job performance is Non Linear: Having the minimum level of IQ for the job is critical (if you're a 100, you will never be a rocket scientist, no matter how hard you try).

But, if you have the min, having more than that doesn't help-- and may actually hurt -- job performance. I am arguing that you can be too smart for your job, but let's save that for another debate.

B

Now that I think about this, I have to wonder how we can know there is an objective degree of correlation between IQ and job performance if the relationship isn't linear. What I'm getting at (but unable to explain adequately, I'm afraid), is that it seems that if you can qualify the relationship by saying too high an IQ is a bad thing, or only a too-low IQ is important, is there really a measureable correlation, or are we crafting the results to fit the expectations? Is there an objective way to describe the non-linear nature of the correlation, or do we make it up case by case?

 

[bpesta22]

Now that I think about this, I have to wonder how we can know there is an objective degree of correlation between IQ and job performance if the relationship isn't linear. What I'm getting at (but unable to explain adequately, I'm afraid), is that it seems that if you can qualify the relationship by saying too high an IQ is a bad thing, or only a too-low IQ is important, is there really a measureable correlation, or are we crafting the results to fit the expectations? Is there an objective way to describe the non-linear nature of the correlation, or do we make it up case by case?

Hi Mike

It's just curve fitting.

Non-linear in this context means not a straight line.

I think-- though any statistician please correct me-- the curve is negatively accelerated with the asymptote being around the range of "min IQ needed"

Wonderlic.com for example has suggested IQ ranges for just about any job that exists.

I think these's examples of minimum IQs are fairly accurate:

Janitor...85
Cop...100
CPA...115
Rocket Scientist....130

So, IQ predicts very strongly which people will be good cops up to about 100.

between say 100 and 115, the relationship flatlines (it's not the case that a 110 is better than a 103; but it is the case that a 100 is better than a 93)

Then, beyond 115, it probably dips down-- suggesting that one could be too smart for his/her job.

The mathematics of the correlation are different when it's linear verus non, but the logic and interpretation and predicative value are just the same.

Any stats people think I got it wrong, please chime in!

Also, to Wile:

I agree, there emotions are important to success and happiness (though I'd prefer to lump the emotional IQ crap into some combo of the big 5 personality dimensions), and with the exception of conscientiousness, none of these aspects correlate with IQ.

Again, IQ doesn't explain the whole chunk of whatever measure of "success" you want to use. But, my guess, is for anything you can measure, the biggest single chunk is explained by IQ.

Edited to correct an error: It's openness to experience that correlates with IQ-- not conscientiousness as I claimed above.