Or, Male Atheists Have Small Penises

Oh, look. The same old, old, old, bad data is being passed around again. We’re going to be a little slower to jump up and claim it this time, right? Consider this repost an incentive.

Ah, what one misses by having lots of social commitments over the holidays. A prime example would be this chart that Hemant posted on Friendly Atheist.

IQ Increases as Religiosity Decreases

Cute, huh? Go, us smart atheists! Yay!

Except for one little thing. [Read more...]

More on Derbyshire

If you’re not up to date on the racist screeching that led the National Review to fire columnist John Derbyshire, start here. It’s a great summary of what Derbyshire has been able to get away with saying and why he suddenly became toxic to the magazine.

Once you are up to date, check out these posts that go into some of the issue surrounding the racist claims Derbyshire made in his piece. [Read more...]

Reaction Times and IQ Tests

As Bryan Pesta recently commented that his attempts to attack my expertise rather than my arguments on IQ is justified by my treatment of him, I thought I’d pull this out of the archive so everyone could judge it. This was originally published on Greg Laden’s Blog, with much additional discussion (with most of Bryan Pesta’s comments on the post, including his intimating that I could get into trouble for linking his study) on my old blog. The discussion of practice effects has been tweaked here for clarity.

In the ongoing discussion about disparities between racial classifications on IQ tests, Dr. Bryan Pesta requested that we consider his paper, “Black-White differences on IQ and grades: The mediating role of elementary cognitive tasks.” Because as he rightly points out, not everyone will have the background to evaluate the paper, I thought it would be helpful to discuss the paper in the context of the cognitive science literature.

[Read more...]

On the Stability of IQ

On a recent post about genes and IQ, commenter JL objected to my statement that the brain is a uniquely plastic organ, and that humanity’s astoundingly extended childhood appears to exist to maximize that plasticity. More specifically, JL objected to my conclusion that given the brains plasticity, we would expect intelligence (and all the other factors included in IQ testing) be incredibly responsive to the environment.

While IQ is highly malleable in principle, in practise it is one of the more stable human characteristics across the lifetime.

The nice thing about disagreements like this is that we can look at the data (what data there is).

[Read more...]

Genes for IQ Found?

Well, no.

The authors tried to replicate published associations between particular genetic variants (SNPs) and IQ (specifically the g factor). They looked at three datasets, a total of about 10,000 people, and didn’t confirm any of the 12 associations.

As Razib Khan says in his post on this, “My hunch is that these results will be unsatisfying to many people.” I’d go further and say that no-one will be happy with these.

[Read more...]

Readings in IQ and Intelligence

Yesterday, Andrew Sullivan linked to my piece on the Canadian polygamy ruling. Unfortunately, around that, he’s spent the last three days how difficult the world is for those researchers who study race-based IQ differences and how we need to look into this more. He knows this because the people who agree that there is something there say the political climate is stifling.

Now, as I’ve noted before, there are plenty of people who study this link, plenty of people who talk about it in various forms of media, and plenty of people who cry politics when factors other than genetics are pointed to as major factors in IQ test differences. All it really takes to know this is to pay attention to both sides of this debate.

The problem is that this can be difficult to do. The racially based IQ story is simple and plugs into our just-world biases. The actual picture involves dealing with complex data and statistical analyses. In order to give an overview of the general data on IQ and heritability, I put together this bibliography a couple of years ago. [Read more...]

Our Ever-Plastic Brains

One point of critical importance in the debate over how much our genes account for variability in intelligence (current status: no effect demonstrated in normal cognition) is that human brains are ridiculously plastic. As would be expected in an organism that can create and function in a wide variety of social structures, our brains can and do structure themselves on the fly. When you see a headline that says, “XYZ Rewires Our Brains!” the only appropriate response is, “Duh.”

A very recent study suggests that this plasticity may be more radical than we already knew.

[Read more...]

Creating Genius

Skepchick Stacey has taken a look at Richard Lynn’s claims, based on IQ testing, that male geniuses outnumber female geniuses 8 to 1. It’s a good post, worth reading in its entirety. I’m going to pull out just one piece of it briefly to talk about the simple math behind the test itself.

IQ tests are deliberately designed to eliminate disparities between demographics. Any questions that test with a statistically significant difference are discarded so that the score variation can only be attributed to differences in individual intelligence. The creators of the tests don’t allow questions in which one demographic scores significantly higher or lower than another. If women consistently scored lower than men on a particular test, that test would be unmarketable because its results would be viewed as biased and invalid.

This applies to both individual (or grouped) items and to overall tests. Tests and questions are created to produce the same mean in males and females in the groups used to develop the tests. However, this means we need to take a hard look at those groups.

Of particular concern is the fact that males far outnumber females among people with learning disabilities. (They’re kind of fragile that way, among others.) In fact, the people who like to tout the genius figures will happily point to the greater representation of males at the lowest end of IQ distributions as proving that their point is somehow “fair.” This is, of course, less impressive when you consider that they don’t expect to ever find themselves in this portion of the curve.

It’s even less impressive when you consider how unfair this higher representation of males with learning disabilities causes the test to be for females without learning disabilities. I mean that literally. A population with this gender imbalance in learning disabilities requires that the test be biased against females when you compare non-disabled groups. If it isn’t, it can’t produce the same mean for both sexes.

But don’t they exclude the learning disabled when creating IQ tests? Not for Weschler tests, at least. Given that one of the main uses of IQ testing is identifying the learning disabled, there are very good reasons to include them.

So as long as IQ tests are built this way, expect them to include the kind of bias that pushes more men into the genius range. And anyone who says that this means something more than that the test is doing what it’s supposed to do? Feel free to tell them just how dumb they’re being.

Reaction Times and IQ Tests

In the ongoing discussion about disparities between racial classifications on IQ tests, Dr. Bryan Pesta requested that we consider his paper, “Black-White differences on IQ and grades: The mediating role of elementary cognitive tasks.” Because as he rightly points out, not everyone will have the background to evaluate the paper, I thought it would be helpful to discuss the paper in the context of the cognitive science literature.

Okay, this time I can’t say I’m not doing science blogging. In order to take advantage of some of the functions of Research Blogging without the setup time, this one is posted at Greg Laden’s Blog.