A theory of IQ: Three mysteries of IQ research

This is the first of two parts. Here, we discuss three mysteries in IQ research. In part two we will propose a theory of human intelligence that resolves them. The three mysteries are the Ashkenazi brain size-IQ outlier, the North-East Asian scientific and economic underperformance relative to their IQ, and the Flynn effect.

Brain size-IQ connection

It has long been known that brain size and IQ are correlated. Modern fMRI-studies confirm this relationship [1]. The correlation is relatively weak. However, even weak correlations can approach unity, if we average over groups and the other influences average out. Asians, Whites and Blacks sort in the same way by brain size and by IQ and the observed differences seem to very similar in terms of standard deviations [2]. Only the Ashkenazim with the highest IQ of all, fall out of that pattern, with an average brain size slightly below the white mean [3].

The Flynn effect

The Flynn effect is the phenomenon that over the 20th century IQ performances rose enormously [4]. In some types of tests this increase is more than 2 standard deviations. The Flynn effect is mysterious because we neither know what the root cause is, nor do we know what this increase means in practice. Nutrition, education, changes in worldview (“scientific goggles”) and several other causes have been proposed, it hasn’t been a slam-dunk for any of these. While the scores went up, people do not seem to be smarter than two or three generations ago.

North-East Asian underperformance

North-East Asians do pretty well. Of all groups out there, they alone have closed the gap to western levels of affluence (or in the case of China, are about to). In what way do they underperform? The mystery lies in the fact that they enjoy quite a pronounced IQ advantage compared to western nations, which doesn’t seem to translate into higher GDP or scientific output. They do well, but not as well as they should.

If we compare Japan and Germany, for instance, we find a pretty similar history: Late comers to the international stage, they went through a phase of nationalism and militarism that ultimately led to WW2 and the destruction of their countries. The countries were rebuild and quickly entered the economic elite again. This makes them ideal for a comparison that highlights the NE-Asian underperformance:

Japan enjoys an IQ advantage that is currently estimated at 6 points (105 to 99 or thereabouts). This should be enough to leave Germany in the dust when it comes to GDP. However, instead they lag behind with 38,428 vs 44,469 USD per capita.

Their population is 50% larger. Their work hours are 50% longer. Their total GDP is higher and the percentage of GDP they put into research and development is higher too [5]. Still, the Japanese lag behind the Germans in most indicators of scientific output [6].

There are several competing explanations that revolve around a lack of creativity, curiosity or testosterone [7]. Or too much conformism and hierarchy. La Griffe Du Lion proposes that it is the verbal IQ that determines GDP (and apparently scientific output) [8]. This would resolve the paradox, because while the high NE-Asian IQ depends on a very high mathematical-spatial IQ, in verbal tests they often lag slightly behind Europeans.

However, this explanation is only mathematically satisfying. Why would verbal IQ be so exclusively important? Aren’t the quantitative skills the most valuable on the labor market?

[1] Big brained people are smarter

[2] Estimating the genetic IQ and genetic brain size of many races

[3] Jewish brain size

[4] The Flynn effect

[5] R&D spending by country

[6] Scientific output country ranking

[7] Why do NE-Asians win so few Nobel prizes?

[8] Smart fraction theory 2: Why asians lag

One thought on “A theory of IQ: Three mysteries of IQ research

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s