The meta-analysis that wasn’t: assessing Flynn Effects through diachronic change in ICV

A while ago I was conducting a meta-analysis on diachronic variation in cranial volume measurements for different East Asian populations. I got into the project after being inspired by Lynn’s suggestion that the Flynn Effect is primarily nutritional, as presumably this would also show an effect on height, head size, and thus ICV. It could even be possible to control for ICV changes to show only the direct change to IQ over time, which would be a more rigorous way to compare Flynn Effect magnitudes. What a great idea, I thought.

Unfortunately as I got deeper into the project, I realized that virtually all of my data couldn’t be sourced back to any obtainable research. A lot of numbers were sourced from papers that were only available in physical archives in Japan or Korea, so I did what any good researcher does and promptly gave up.

However, even with the limit to my data integrity acknowledged, I was still able to get some plots of the cranial volume measurements that show some interesting results. Here’s a scatterplot I built using values from all studies I could find; the x-axis shows the year of the study’s publication and not the date of subject collection, expiry, or measurement. Note that all datapoints are n-unweighted (raw averages).

While initially there doesn’t seem to be much to say about this graph, it’s noteworthy that there don’t appear to be (when plotted in this form) any outliers, but two relatively clear clusters by gender. Clearly the female cluster is far less grouped than the male one (the source of its statistical insignificance that can be clearly seen in the following trendlines) but both clusters have mutually exclusive ranges, which are interesting. Since all of the studies here had sample sizes that were above 20 we’d expect distributions to be roughly normal, meaning that group-level sex differences in ICV are likely very reliable. This of course is no surprise seeing as ICV is effectively a function of body size and height, which are also variant with respect to sex in the same way. This becomes more obvious when we ignore the insignificant ethnic variation and go purely to the sex differences:

Overall it is fairly clear that ICV as reported in studies is increasing overtime. However, note the lack of any female reports going back beyond the early 1920s? This is a sign that our data is shitty. For many of the earlier studies no sex information was present, and although in some cases I was able to make informed estimates based on the averagees (i.e. a mean ICV value close to 1500 is almost certainly male or mostly male in content) it was never really certain how accurate or representative the values might be. However, if we are correct in inferring that earlier studies likely did not disambiguate male and female samples (as opposed to exclusively using male samples) then it could be suggested that the actual observed gap would be even greater, seeing as the female values would go down and the male ones would go up. This of course would throw the trendline for diachronic variation into doubt, which is currently strong with p value < 0.05 when excluding females.


Email me if you want the full dataset to work on.

Narratives of conversion

A while ago I was doing a research project on converts to Islam and their motivations through qualitative self-reports, which I collated into a series of ‘types’ or narrative trends. Here’s what I found.

For many in the increasingly multicultural, heterogeneous, disoriented West, Islam provides a specific identity by which they can define themselves and their relationships with other entities in the world.

A young guy at my gym (16) who recently converted to Islam is an example; he is son to a white father who abandoned his black immigrant mother before he was born, and described to me the difficulties of identification at school. He was being raised by a black mother in a black neighborhood, but looks more white. Islam grants him a consistent in-group with which he can find solidarity. He knows absolutely nothing about the theological aspects of Islam and hasn’t read the Qur’an, but takes pride in his new identity as a Muslim and often drops standard Muslim vocab (hamdulillah, mashallah, etc).

His newly obtained insider status he displays frequently, saying ‘we’ (Muslims) and ‘you’ (non-Muslims) even though he only converted a few months ago. Previously, as a ‘white’ looking kid yet also a product of a black subculture, there were presumably fewer individuals he could feel connected with in the same way.

The West is increasingly irreligious, but the human need for spirituality remains a motivating factor in many of our lives. We naturally seek out something to fill that void. For many, Christianity seems ‘weak’ and ‘feminine’ in comparison to a much more ‘muscular’ and uncompromising Islam. The level of piety displayed by self-declared Christians, many of whom do not go to church and the vast majority of whom do not do anything ‘Christian’ above that, might also seem ‘shallow’ in comparison to Muslims, who (ostentatiously) display strong degrees of religious attachment and faith.

For some, then, a quest for spirituality and a desire to know the ‘truth’ of existence can drive them towards religion; Islam will often be the obvious choice due to its constant proselytizing, its muscularity and universal presence, and the unwavering faith (and total lack of doubt) of the vast majority of its adherents. As a convert, I myself fell into this category.

Islam is a religion, but that religion mandates a specific way of life for its adherents in a way that no other organized religion does. While this is authoritarian, many people in the West, especially young people, feel that this gives them a sense of purpose; they are no longer sleeping in until 1 in the morning on weekends, but waking up for fajr at 5 AM.

Not only that, but they have a clear template for how to live their lives; do this, do that, and things will all turn out fine. For many, these firm guidelines bestow upon their lives a sense of drive that would otherwise be lacking. There are also clear tiers of accomplishment and progression that allows someone to feel successful; memorizing surahs, for example, or improving one’s tajweed gives a sense of achievement that is otherwise lacking for many people, especially those in dead-end jobs or careers.

Indigenous women are the largest source of converts to Islam in Europe. Islam assigns women a clear role as homemakers submissive to their husbands (4:34) and although this may seem counterintuitive, some women (not only underachievers) are quite happy to be just that, and feel uncomfortable with an increased burden of responsibility placed upon them by feminism and the equality of the sexes, which demands they do more. For them, Islam gives them a more ‘traditional’ template which not only does not punish them for not taking on a career and being a stay-at-home mom, but in fact rewards them for it.

I feel like narratives around conversion in prisons is also something worth examining, as it is happening at an alarming rate in the UK and often results in the emergence of religious gangs within prisons openly exposing extremist views, which can impede reintegration. I’m currently reading more on this phenomenon.

Another type, the ‘decolonialist’ type of conversion, is observed particularly in the United States, where Islam has been seen as a more authentically ‘African’ religion, ever since the 1930s with the founding of the Nation of Islam movement. Prominent individuals like Malcolm X have popularized this model, and many black Americans feel that they have a collective grievance against Christianity for slavery which is best solved by turning to Islam. The MASSIVE increase in appropriated names of Arabic origin in the black American community is symptomatic of this trend.

The ideological benefit curve

Before I became more biologically oriented in my thinking, I used to be super into ideologies – not any particular ideologies, but the very idea of ideologies as a category. It’s virtually impossible to have anything approximating a scientific discussion about ideologies, because even the very word is a semantically and semiotically loaded cultural construct; as Žižek says, we cannot look at ideology as we inhabit ideology. However, there are still a few interesting things to say about the topic. Take the following example:

This is one of the goofy graphs I made on the topic, that just so happens to encapsulate an interesting idea (ignore the numerically ordinated axes for a moment). The question is – who benefits most under a specific ideology? What the curve shows is that an authoritarian society will provide maximal benefit to those unable to coordinate their own affairs, simply because in such a society your affairs are already done for you. However, strong-willed thinkers and creative types will probably suffer in such conditions, lacking autonomy over their ideas and self-expression.

An individualist society, by contrast, will provide maximal benefit to those who have the aptitude to organize their own affairs and excel in absence of supervision. Yet such a society will necessarily provide less assistance to those who are less able to organize their own affairs – some of whom will be desperately in need of such assistance.

So which society is better? One constant feature of human sociality is that there rarely appears to be anything that is objectively ‘better’ than anything else; everything comes down to tradeoffs and opportunity costs. So if you’re Nikola Tesla you’ll probably do better in the individualistic United States, but if you’re a lonely depressed person suffering from the atheistic anomie that seems to grip Western civilization as of late, then you’d likely be better off staying in Serbia. At least homes are cheap there.