Tuesday, May 23, 2017

Social class and fertility in 21st century America

Several years ago I looked at fertility among whites by sex and intelligence (as measured by Wordsum scores) and found that to the extent that the trend is dysgenic, it is almost exclusively so among women. Among whites, high IQ men have as many children as low IQ men do. That's not the case for women, and education--rather than intelligence per se--looks like the 'culprit'.

A basic understanding of mating market dynamics makes this easy to comprehend. Many men have no problem marrying 'down' in status. It often makes for a happier relationship for both sexes in those situations. Heartiste calls this the Boss-Secretary Sexual Strategy (BoSSS).

Women, however, do have a problem marrying down. And by the time women have spent a decade in college climbing the social ladder they're not as attractive as they were when they started, while men who spend a (productive) decade in college are more attractive than they were when they started.

Here's looking at that from another angle, that of social class. It's elegant in its simplicity and utility in that it combines several attributes--intelligence, income, education, etc--into a single variable, albeit a self-reported one. The GSS allows four responses for social class; lower-, working-, middle-, and upper-, with the distribution among non-Hispanic whites at about 5%-40%-50%-5%, respectively.

All data is from 2000 onward among whites aged 45 or older for contemporary relevance, to avoid racial confounding, and to allow family formation to have occurred. Mean number of children among whites, by sex and class:

With social class, too, a 'dysgenic' trend emerges among women but not among men (or a very attenuated one, anyway--there is still the issue of parental age at birth).

I've seen speculation that intelligence, especially among boys, correlates more with that of their mothers than their fathers. Here's to hoping that's not true.

At first blush it seems unlikely that intelligence is primarily determined by the mother. It would make a seemingly evolutionarily important trait, intelligence, an almost random byproduct of other selection forces. Intelligence is not high on the list of what men look for in women. Women value intelligence in mate selection more than men do, so it would be odd if the mother's intelligence was primarily determinative of the child's.

GSS variables used: RACECEN1(1), HISPANIC(1), CHILDS, SEX, AGE(45-89), CLASS


Jim Bowery said...

Differential Fertility, Human Capital, and Development

TL;DR He discounts women-specific measures and claims it is "parents' education level" that drives down fertility.

I doubt it -- particularly since there is such a pronounced correlation between education and TFR on the female side.

However, he doesn't make his data or software available for independent verification so one would have to have the support of some place like Princeton to replicate.

Audacious Epigone said...


From what we can glean from the GSS, it looks like you're right. There appears to be (in the US, at least) a slight inverse correlation between educational attainment and fertility among men but it is much more pronounced among women.

The aesthetic quality has deteriorated for reasons I'm unsure of, but at least the data is publicly available for independent verification!

Anonymous said...

This is intuitive. Like Black women and Asian men have it rough in mating so do uneducated men with no prospects and super educated lawyer cunt women with PHDs

a reader said...

The claim that a boy's intelligence is inherited somewhat more from his mother than from his father isn't only speculation - but I admit it's my fault to mention the idea without offering any evidence for it. It is based on the fact that a boy has just one X, from his mother, and X chromosome has a substantial impact on intelligence, because there are many forms (caused by many genes) of X linked mental retardation:


There are scientific articles and a book on this subject:

"Genes for intelligence on the X chromosome"

"Sex Linkage of Intelligence: The X-Factor"

"An investigation of Similarities in Parent-Child Test Scores for Evidence of Hereditary Components"

In the last one, on page 70, there is a table with correlations of scores at "Mental Arithmetic Test" and "Identical Blocks Test": mothers-sons correlations are bigger than mothers-daughters and fathers-daughters correlations and those in turn are bigger than fathers-sons correlations. (But there are also, at page 64, other tests that don't follow the same rule.)

(Sorry if there are language mistakes - as I said, English is not my first language.)

Feryl said...

This paints a disturbing picture. The lack of stigma surrounding single motherhood leads to prole women getting knocked up by cads with varying degrees of effort among either party to stay together. Indeed, the quickest ticket to welfare is single motherhood, although the gibs are not as generous as they were before the mid-90's.

Also, recall that in the striving arms race, women began to gain college grad. parity with men in the early 1980's. No matter how dumbed down standards get, we're still going to see a greater number of high IQ women attending and graduating than those who are less endowed. Boomer women were substantially more likely than previous generations to feel entitled to "having it all", rather than settling for the superficially boring life of settling down early without much fuss. Subsequent generations aren't really any better, since, after all, striving has gotten worse since the 70's and 80's. Be that as it may, lower IQ women are more likely to be intellectually intimidated from seeking greater education, not to mention being more prone to hedonism ("I'll get laid by several jerk boys, and maybe I'll get pregnant and the dude might not stick around, but Uncle Sam and my family will come to my rescue anyway").

Good insight about the hourglass running low. It's not just that striving women are losing years of fertility per se; it's also that the later years offer less, um, bang for their buck. It can't be a coincidence that Late G.I./Silent Gen women married so young in the 50's in which the baby Boom peaked (continuing into the early 60's). Marrying young+marital and economic stability+non-striving culture=lotsa kids.

chris said...

Mothers intelligence would only matter more than the fathers in the sense that a dumb mother would not only provide dumb genes but also a poor developmental environment for the foetus due to the mother making dumb decisions. i.e. smoking, drinking while pregnant.

Jim Bowery said...

A rhetorical failure of the OP is that the population effect of differential heritability between mothers and fathers, if it exists, is almost certainly washed out by the large effect education has on female TFR.

That large, certain, effect should be front and center at the start and end.

Audacious Epigone said...


In the sense that those groups have it relatively tough, yes (though Asian men are not disproportionately lower class nor black women disproportionately upper class).

a reader,

I don't mean to be dismissive. I can't speak to the evidence so I won't try to, though it does seem worth noting that it would be a curiosity of sexual selection if it turns out to be the case. Anything similar with regards to other traits that have more influence in one sex's selection but that are more heritable from the other sex, like, say, height?


Marrying young+marital and economic stability+non-striving culture=lotsa kids.

When we talk about an American golden age in the 50s, this is about the pithiest summary of why I've ever seen.


Which is why it would be an odd curiosity for selection for intelligence to be strongest between mothers and sons, though I understand the mechanism for how it would occur.

Dan said...

It does not seem likely that the mother is the primary determinate of intelligence for the simple reason that intelligence is controlled by a huge number of genes. What is the likelihood that those genes are concentrated all concentrated in the X-chromosome?

The father and the mother contribute roughly the same number of genes.

Wikipedia tells us
"The DNA in the human Y chromosome is composed of about 59 million base pairs.[5] The Y chromosome is passed only from father to son. With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest-evolving parts of the human genome. To date, over 200 Y-linked genes have been identified"

That compares to 98% similarity overall.

It would seem likely that important genes for intelligence are found ONLY on the Y-chromosome, which has the greatest distance between us and chimps. This seems to find support in the fact that 100% of Fields medalists, 99% of Nobel science prize winners, 100% of the top 100 chess players in the world etc. etc. have been men.

Of course if a scientist were to publish such definitive proof that men are smarter than women, the Cathedral would have to see that they are immediately dis-employed. And then their department would have to be shut down. And then their University would have to be nuked from space, just to be sure. Maybe the Chinese will tell us more, since science is dead in the West.

Dan said...

Oh look, the guy reporting on the incredibly rapidly evolving Y chromosome was crime-thinker Nicholas Wade.


If I was a billionaire, I'd fund narrative-destroying science to my heart's content.

Audacious Epigone said...



IIRC, Rushton argued that male mean IQ was a few points higher than female IQ, but that doesn't seem settled to say the least.

If I was a billionaire, I'd fund narrative-destroying science to my heart's content.

Failing that, find employment inside the Cathedral and quietly chug away without drawing too much attention to yourself--like Wade did at the NYT for so many years.

Dan said...

Here's Milo --


One does not need to know much genetics to realize that there must be a whole lot of good stuff on the Y-chromosome.

I cannot imagine what it must be to be a lefty. The world is so full of these horrible coinkydinks (sp?) that keep happening over and over again, for no reason at all. It is frustrating when the Cathedral conspires against you, but for them the universe conspires to mock their version of reality in every moment.

Audacious Epigone said...

Razib Khan on the speculation:

"effect size is not strong if that was legit. only a tiny % of genome is x remember"

Feryl said...

"When we talk about an American golden age in the 50s, this is about the pithiest summary of why I've ever seen."

And that's why the Left hates the 50's. Nobody was causing trouble. Nobody had anything to complain about. It may be hard for our generations to believe, but if generational theory is correct, that was why the period was so off-putting to Silents and early Boomers. The G.I.s took credit (mostly but not entirely deserved) for creating the stability and prosperity (to the indifference of Losts and resentment of Silents) of the late 40's-early 60's. By the mid 60's, Silents were entering mid-life crisis stage, not sensing either respect for the things they'd done while also wanting to escape association with the increasingly unfashionable G.I.s. Meanwhile, Boomers wanted to just blow the whole damn thing up and start from scratch.

After G.I.s retired from public life (and eventually life itself), there was nobody around anymore to stick up for pre-1960's culture. Silents and Boomers who ran from cultural traditions and stability have been framing our overall view of things for 50 years at this point, indoctrinating a decent chunk of younger generations along the way to stick it to the "man" (yes, 70 years into the Boomer life cycle, most Boomers still think of themselves as outsiders in the grand scheme of things, a big reason why Marxist horseshit has entombed our intellectual life for the last 40-50 years and also why so many Boomers do not hold themselves accountable).

sillly girl said...

The silent generation was the 1960's radical culture generation. My mother was born in 1946 at the very beginning of the baby boom. In 1964 at age 18 she was married, then pregnant and wasn't leading a damned thing let alone a cultural revolution. Boomers were the sheep. Those who led them were silents. Just google the birth year of any 60's radical, you will not find a single boomer.

silly girl said...

Intelligence carried on the female line?

Seems we could see a pattern somewhere.

Uncles, cousins and nephews of brilliant folks like Newton, Einstein, Pasteur, etc.