Inductivist

Whether you are a social conservative or a eugenicist (let me know if there is a less loaded term), we have experienced an unmitigated disaster in the 2010s.  Both camps want healthy married parents having lots of healthy kids that are raised in a safe home.  Here are a series of graphs to document trends away from this:
















The percent married has dropped from 68% in the 1970s to 44% in the 2010s. And look at the trend in never-marrieds: the rate doubled over the past five decades from 14 to 28%.
















The trend is sharper if we only look at young people (ages 18-34). Among this group, the percent married has plummeted from 61% to 30% while the percent never-marrieds jumped from only 30% to 64%. In a word, early marriage is collapsing.
















Accompanying the decline in the institution of marriage is fertility among intelligent women. This graph shows the number of kids for women ages 40-59 with IQs of 118 or higher.

We see a collapse in the number of these women having four children, a strong increase in the percentage having two kids, and most disturbingly, a doubling of childless women--from 15 to 31%.
















A current priority of elites is to get women as educated as possible so they can have the type of careers that give them maximum autonomy.

The social conservative and the eugenicist, by contrast, know that prioritizing female education kills fertility among intelligent women and renders a society incapable of replacing itself with talented people. Maybe there is no necessary connection between education and fertility, but under current conditions, the link is very strong.

The above graph shows the tremendous growth in four-year and advanced degrees among American women. The number of intelligent women like my mom who finished high school, got married, and had four healthy children has become a rarity.
















The success of the gay marriage movement might be the most visible family-related loss that we social conservatives experienced in the past decade. The graph above shows the complete reversal of attitudes among young people (ages 18-34) concerning gay sex. (The General Social Survey doesn't have a question about gay marriage that spans the decades.)

The popularity of same-sex marriage is an important indication that Americans are replacing the belief that an important life purpose is to have a large biological family with the belief that the purpose of life is self-fulfillment and that being married or having one or two kids (biological or not) might work toward fulfillment for some people.

I suspect over the long-term that reproductively-oriented people tend to inherit the earth. Muslims and Africans might eventually displace Western Europeans. More virile people might eventually displace sterile Americans as well.

We saw in the last post that religious women are having more babies than women who never go to church. What about men?  Here a graph for number of children for men ages 45-60 (GSS, N = 1,251):
















The pattern for men is even clearer than for women: guys who attend more than once a week have a much higher mean (2.38) than those who never go (1.61). That's roughly half of a standard deviation difference.

Is this religiosity-fertility link explained at all by differences in attitudes?  Do religious people want more kids?  Look at the graph for the same age ranges (GSS, N = 2,173):
















Males are green, and females are purple (I'm a dude, so I won't try to give more precise colors).

There is a small tendency for more religious people to idealize larger families. It seems too small to explain much of the reason why the religious have bigger families. It's probably due to getting married earlier and less willingness to get an abortion if you get a surprise.

NOTE: You have read an updated version.  The earlier version had the error of leaving in cases of those who answered "whatever number people want," cases that were scored an 8.  The results you see above omit these cases (about 6% of the sample). 

Social thinkers have been predicting the end of religion for many decades.  For example, Auguste Comte (1798-1857) predicted that religious faith would decline as scientific knowledge spread.

Over the past two centuries, religion has proven to be more resilient than thought, but there has been a serious decline in regular church attendance in the US in recent decades, and confidence in the existence of God has slipped some, too.

Modernists like Comte were not aware that at least one powerful factor might work against their hopes of a secular world: genes.  Studies have found that religiosity is influenced significantly by genetic differences. 

And there's a related factor: the correlation between religious involvement and family size.  Look at current data for American women (General Social Survey, women ages 40-55, N= 1,441):
















Women who never go to church average 1.92 children, while those who go more than once a week have a mean of 2.48 offspring.  The gap between the two groups is about four-tenths of a standard deviation, a medium-size difference.

Notice how the least fertile women (1.66 kids) attend once per year.  (I'll document in a future post that atheist women have more kids than agnostics.)

Religious people tend to be more conscientious and agreeable than the irreligious, and fertility differences are favoring these genetically-influenced traits.

If the greater fertility of religious women turns out to be a long-term trend, evolution might work against secularization.  Combine this with the mass movement of religious Muslims, sub-Saharan Africans, and Hispanics to the developed world, and Comte's vision might be undermined. 

The Nordicists, under the leadership of Madison Grant, could be criticized for many things, but I join with author Jonathan Spiro in mocking their sterility. In his book Defending the Master Race, Spiro must have mentioned 30 eugenicist leaders who died without fathering a single child. Nowadays (and perhaps even then) there would be nothing but whispers that these guys were closeted homosexuals. 

Yeah, yeah Grant devoted his entire life to doing what he thought was best for the country, but how about listening to your own lectures?  

I agree completely that society benefits when the most successful have lots of kids, and the less successful have few (although coercing people is fascistic). So in that spirit, I looked at General Social Survey data and calculated percentiles for the number of offspring had by smart people (WORDSUM of at least 8) who were ages 40-59 during the surveys conducted from 2000 to 2008. I also took the liberty to label guys by their productivity:

UPDATE: The eugenicists were like Shakers.  If you're starting something like a new religion, you have to either convert lots of people or breed them if you're going to last. The Grantians seemed to think their prestige and corner on the Truth was enough to make an enduring movement. Meanwhile, the Boasians cranked out PhD after PhD, and took over anthropology departments all across the country as well as the American Anthropological Association by sheer numbers. Their cultural determinism was no closer to the truth than Grant's biological determinism, but truth had nothing to do with who won.  

There is reason to believe that a Darwinian outlook increases fertility among elites.

Using GSS data, I formed two groups. The first is of math, computer, and physical scientists (n = 126). The second group includes biologists, agricultural and medical scientists, physicians, and veterinarians (n = 85). I followed this strategy on the assumption that the two groups are similar but that evolutionary realities are closer to the center of the latter group’s worldview.

Next, I calculated the mean number of offspring. I limited the sample to people between the ages of 45 and 69. For the first group, the average is 1.62 children. It’s 2.04 for the biological group. Confidence intervals overlap just a bit, so the difference is not statistically significant at the .05 alpha level (two-tail test).

I still take this as evidence that a Darwinian view might encourage smart people to have more kids. In an age where fewer and fewer elites find religion credible, we need to be Darwin’s evangelists. Of course, values cannot be derived logically from the fact of evolution, but I think natalism could be psychologically compelling to many if their worldview were Darwinian.

A couple points about abortion and achievement: One argument made in the comment section of the last point is that smart, pregnant girls give up bright futures if they don't get an abortion. It is certainly true than teen motherhood makes it harder to have a successful career. Not impossible, but harder.

One currently popular belief is that if children are going to grow up to become well-adjusted adults, both mom and dad must devote every waking moment to their development. The best research tells us that this is simply not true. If kids were randomly assigned another pair of parents, they would turn out pretty much the same. Research also tells us that day care is not bad for children. So, to all you young women contemplating an abortion, it might be harder, but you don't have to kill your child to get ahead. You might have to give up spending as much time with the little guy, but trust me, if you're the ambitious type you'll enjoy your children more if you're not with them all day. Drop the idea that Junior needs you that much.

Another reader comment was that an intelligent, pregnant teen can always have kids later. While this is true, one demography truism is the longer you wait, the fewer the children you have. I looked at GSS data and found that a delay of ten years translates into one fewer kid for women with the highest IQ (WORDSUM) scores.

I'm not concerned about an overall lack of kids: I'm worried that we're having too many unintelligent kids and not enough smart ones. At the same time, it makes sense for a society to put its female talent to use. While there is tension there, challenging the notion that kids need mom 24/7 can help us achieve both goals.

After reading's Razib's post on eugenics, I wandered what the trends are in approving of an abortion if there is a good chance of a birth defect. It turns out that support has been dropping for a decade. The percent approving went from 81.8% in 1996 to 72.9% in 2004. 2002-2004 was the biggest two year drop, and I'd be interested to see the 2006 numbers. The samples were all over 850 people, so the numbers should be fairly accurate. Of course, approval numbers are still high, but as genes moves front stage, we might see some backlash.