"I expect to die in bed, my successor will die in prison and his successor will die a martyr in the public square. His successor will pick up the shards of a ruined society and slowly help rebuild civilization, as the church has done so often in human history." -Cardinal Francis George

Wednesday, April 24, 2013

Natural Fertility: How many kids will a woman have in her lifetime?

If humans are ever put in a zoo by an alien race, and we are left to our own devices with plenty of food, medicine, exercise and safety, and with an ideology that neither shuns children or demands loads of them, how many children would women have?

Well it turns out researchers have been asking this question for a long time.
The Amish

I just read an interesting research paper called Population growth and fertility paterns in an Old Order Amish Settlement. by L. P. Greksa.

It looks at 1,337 Amish wives in the Geauga settlement in Ohio from 1908 - 1993. The Amish are considered an ultra high fertility group (in today's standards) straight out of the 19th century in their breeding habits, yet they use modern medicine. This makes them perfect for studying and looking at what the rest of society would look like if we still had traditional 'pro-fertility' attitudes. The conclusion of the paper says that the women do not attempt to control their fertility either up or down in any major way. To the researchers, this means the group in question is a "natural fertility population", which they desire to define so as to have a benchmark to measure from.

So how many babies do you think these perfect specimen, natural fertility, married Amish women have? Are they all like Michelle Duggar with 19 kids per woman?

Is it more than 19? Does it round down lower to around 10? (that was my guess). Let's see:
The mean number of pregnancies per married woman was 7.7 (SD 3.6). Fifty-two pregnancies terminated  in a stillbirth and 41 women gave birth to one set of twins, four gave birth to two sets of twins, and one woman gave birth to four sets of twins, for a twinning rate of 13.9 per 1000 pregnancies [1.4% -DM] resulting in a live birth. Mean completed marital fertility was 7.7 (SD 3.6) births, ranging from 0 to 17 births. About 3% of these women were childless while 28% had 10 or more births.
The men get married at 22.2 years, women at 21.1 years. The birth of the first child is consistently a year later when the woman is 22.1 years. The second child is consistently born 1.5 years after the first, with subsequent births spaced just under 2 years apart. For the period studied ('08-'93), the age of the last birth has dropped from age 40 to 35, marriage age and first birth age both dropped by one year, and spacing also dropped slightly. The fertility rate also dropped by 1 child during this time.

In this study, the 7.7 children per woman is per married woman, and I am unclear if this study ever actually says what the Total Fertility Rate for the community is. It does give data on sterile couples (3%), stillbirths and twins though. After all that is factored in, the number is still 7.7 per married woman, and of those with children the average is 7.94.

Normal Fertility Rate

So what does this all mean? Almost all of these numbers were different than I expected. I expected them to be marrying younger, having more kids for a longer time, and I expected the natural infertility to be higher. Instead the study shows that

 normal human women have a very reasonable 7.7 kids within a 14 year timespan.

The biggest family of all 1,337 of these women had 17 kids (so even Michelle Duggar would have a big family in this Amish community). And only 28% of families had 10 or more kids, with ony 3% of couples being infertile (way lower than I thought). Another fun fact is that the 7.7 "completed marital fertility rate" is not comparable to the "Total Fertility Rate" we are used to seeing. Total Fertility Rate includes all women of childbearing age, which will include singles who will never have kids such as nuns, the severely disabled, or those who otherwise have a vocation other than marriage.

If 30% of our study population remained unmarried and childless, the Total Fertility Rate would be still be 5.4 children per woman! That is three times the U.S. Total fertility rate!

My take away from this is just how incredibly... normal... and natural all these numbers seem. As a father of 5 myself, who can easily imagine more kids in my home, but find it harder to imagine having 10+ kids, I took comfort that 7 or 8 kids is naturally where fertility will end up (on average) for people in a healthy marriage. It is so easy to believe our culture that says having 3 or 4 kids is "a lot". Well it just isn't. In fact those 3 or 4 kids are 
below the average for where a couple will naturally be.

Our American TFR of 1.9 children per woman is now "well below" the replacement level of 2.1 needed to just keep a population steady. And much of that number is from new immigrants, who quickly adjust their fertility habits in the first and second generation, and anyway the countries who have been sending immigrants are no longer doing so and will soon stop. The American middle class is down to a TFR of 1.6 and falling.

I am not saying couples with zero or 1 or 2 kids should feel second class. Unless they have that few because they have an unhealthy view of children and their place in marriage. Obviously couples can be infertile (even 3% of Amish are), can have vocations or health issues which make it prudent to limit the number of kids, even to zero potentially. But these exceptions prove the rule that families should naturally be much larger than they are in our culture.

The exceptions that prove the rule.
3% infertile couples is... 3%. Get over it! That is a very small amount of couples! Yet if I had a nickel for every time I hear this as a reason why every family I see has only 1 or 2 kids, I could buy my own tropical island. Even factoring in infertility, the normal fertility rate for married women is still 7.7 kids

All parents have mental issues to some degree that having more kids may make worse. But are Amish women with 8 kids going insane by the truckload? I don't think so. Will having child number 4 really push most women over the edge? Or is it more likely that only a small percentage of parents have true psychiatric problems that make it unwise to have more kids? Even if I were generous and assumed that 30% (!!!) of women went clinically insane the day their third child was born, and never had another child, the Normal Married Fertility Rate would only drop by 1.41 kids per woman to 6.29.

Going to college extends time of marriage and first birth.
This is another very valid reason that a woman's fertility might be reduced. And using our Normal Married Fertility Rate of 7.7, with women becoming mothers at age 22.1, we could account for a generous 2 years of post college time to get married and conceive, and then she gives birth at age 24. That is a full six years after high school graduation, plenty of time for a college degree or two. So to account for this lost 2 years from her reproductive clock, lets deduct a full child from every woman in our study. That's right folks, we will assume universal college education from our women! They all lose one child and our average drops to 5.29.

Working outside the home. Some people say that families are so small because women have to work, and no longer have the time to give birth and to properly take care of lots of kids. To this I say... yep that is true. This is on the one hand a valid reason to reduce the number of kids you have, but at the same time is a bad excuse because it should not be happening nearly on the scale it is. Ask any woman to list the most fulfilling aspects of her life. If she has kids, she will have them higher on the list than a career. Yet the same woman will often say that her career is the reason she did not have more children. This makes no sense. If raising good human beings from childhood to adulthood is the most important job on earth, which we all agree that it is, then why do so many women choose something less fulfilling to fill their time? This one is hard to estimate, but my guess that in a healthy society no more than 30% of married women would want to work outside of the home in such a way as to reduce normal fertility. If these 30% each limited themselves to an average of 2 kids each, our average drops to 3.88 kids per married woman.

So assuming all the modern things we blame for our low fertility, we are still left with 3.88 kids per married woman in a healthy society.

Now let's take this society and assume that 20% of the women do not get married and become nuns or run businesses or whatever (20% seems like a lot by the way). After we factor that 20% in, we are still left with 3.1 as our total fertility rate. 3.1 is considered by demographers to be a high growth rate and significantly higher than the replacement rate of 2.1.
You might ask: Where the heck are you going with this you long winded weirdo?
Here is my point:
If we believe what our culture tells us, that it is perfectly fine that families come in all shapes, colors and sizes, and arrangements, with same sex parents or divorced parents, with any number of kids, with either mom or dad (or both) working and sending junior to the public school... if that is really true... and all that is just so *great* for families and we live in such a wonderful new springtime of humanity... then why do all the families I see buying into these modern notions look so much the same, with the same abnormally low number of kids (0-2), with most of the moms working outside the home and still doing the housework**, with 50% divorce rates?

Instead of being progressive and bold, our new culture is homogeneous and boring.

On a basic level using the simplest of math, think about it like this: Not every woman is called to marriage. And of those that do marry, I would argue that most married women will have various trials (described above) that prevent them from having lots of kids.
So if both of these things are true, and the replacement fertility rate is 2.1 children per woman in general, then how can we think that having 2 kids per married woman is healthy? Married people need to be having far more than 2.1 kids for a society to simply replace itself because they need to be having the kids to replace those who will not or cannot have them. As I have shown above, when we see a family with 3.88 kids we should be thinking "that is an average, healthy family size". And considering how conservative I was with my math (20% of women not marrying would be very high), we should consider the 3.88 to be on the low side.

So the next time you see a family with 4 or 5 kids, remember that that is a very average number. And a family with 8 kids should look no stranger to us than a family with only 1. We cannot let our suicidal culture dictate to us what a normal family size is. The simple, scientific fact is that a normal, healthy family size, even in the modern world with all its challenges, will be far larger than is culturally acceptable.

*If we were to translate the 7.7 married fertility rate into a Total Fertiltiy Rate, it can only go down because we are adding in non-breeding women. Let's pretend 10% of all Amish women never marry. If the married fertility is 7.7, then the total fertility would drop to 6.9. Married women would still have their 7.7 kids, but overall, the Total Fertility Rate would drop due to the 1 in 10 of all women that will never reproduce. If the number of unmarrieds rises to 30% of women in this population, the TFR drops to 5.4. If fully half of women in our naturally fertile society never marry and reproduce, then the total fertility rate drops to 3.85. 10-30% of women never marrying and procreating does not seem all that unreasonable. Particularly if marriage is seen as the important vocation it is, to not be entered into lightly. I think one thing that is perhaps not natural with our Amish case study is the high marriage rate, which I suspect is well over 95%. So although their family fertility is "natural", perhaps the number of families is unaturally high due to their anabaptist religion and a lack of vocational choice.

**The studies I read on European demographics last week had hard evidence of this. Unfortunately I cant recall where the data is located. But it was astounding how even in northern Europe, where women are supposedly so advanced in equality, they still do most of the housework.


  1. I came across your post on another blog expressing a desire to see a religious order for families. Do you know about the Plain Catholics? They've been around for about 110 years or so. http://plaincatholic.webs.com/

    There's also the Brothers and Sisters of Charity in Arkansas http://www.littleportion.org/
    who have families living on the same monastery grounds as the celibates in vows.

  2. M,
    I think I bumped into you before on the Catholic homesteading forum. The Plain Catholic thing seems very Amish to me, which gives me pause. There is a lot to like about the Amish, and much that they have retained that our culture has lost, but overall, they are still an Anabaptist cult. Some type of religious order for families sounds interesting to me, but the Plain Catholic thing just looks like they are trying to copy the Amish. Also, where are they? How many are there? 110 year history? I can find no information about Plain Catholics online other than what looks to be one guy with a website. Which when you think about it is ironic. Having said all that, if Plain Catholics grow and become a community of hundreds of families (or even dozens) and seem to be thriving, AND they recieve Church approval, I would be happy for them. But what I pictured for a family religious order was something different. Not exactly sure how, but something about the Plain Catholic thing doesnt sit right with me. Cant put my finger on it though.


    David Meyer

  3. Wow!!! Awesome post, Uncle David!!! I very much enjoyed it, especially since I have been studying the effects of feminism in our modern culture. ....and seriously, you should consider starting up a nickel business and pursue that tropical island. It really might work. (Also, my parents say to tell you that they really liked this post too!)

    ~Mary Ellen

  4. Hey thanks Mary! This was a topic I could find no info on so I did the research myself. It is so weird to think how normal and average having 5+ kids should seem to us. It really shows how far off the rails our culture is getting. If you have not seen Demographic winter

    (and Demographic Bomb, the sequel) you would be interested. They talk alot about feminism in there.


  5. Mary, just thought of something I wanted to run past you as well...

    What are your thoughts on the lack of vocational choice for the Amish? It was my thought that although within each married family the data was reliable for the fertility (it is natural), the high amount of married people was perhaps skewed (an unnatural, or overly realized patriarchy). I know that for most of western history (certainly pre- and also post-reformation) and even during very traditional and patriarchal times, there has always been the option for women to become nuns, and often other options of pursuing things other than marriage/children without being seen as odd. But for the Amish, my impression is that they would have more expectation toward the norm of marriage/children. Is this right?
    If I am right, then the feminists may have just the slightest correct point in thinking women in a patriarchal society have fewer options (or less options than they should). But it is not the patriarchy per se that is wrong, but perhaps just overly realized towards focusing on one vocational choice (marriage) for men and women. But if this is true, there will be men in that society that are likewise getting less options and being pressured towards marriage, so it would not be a “feminist” problem only.
    My feeling is that the feminists have a grain of truth that patriarchy had led to an over focus on marriage as a vocational choice (although they ignore the effect of this on men of course, and they ignore the fact that marriage is a fabulous vocational choice for both people!).

  6. Hey, cool! I will check out Demographic Winter! And thanks for doing all the research. I may try to work this post (or some of your points) into the post I'm working on about feminism.
    Very interesting question. I do think that feminism has some valid reasons for their 'crusade' if you will. The problem with the human race is the lack of balance between feminism and male chauvinism. The pendulum swings back and forth from one extreme to another. I actually think we have it pretty good here in America because we have the choice to be or do pretty much whatever we want and there will probably be a group of people for us to form a community with and therefore not feel odd.
    As a single, eligible young lady, I am glad for the ability to do something with my single time and not feel odd for not being married or pressured into marriage just because that's what is next.
    In that sense I do not think the Amish expectation of marriage is o.k.
    I guess I would want to see the statistics of happy Amish marriages: how many Amish marriages are arranged, betrothal rates, etc.
    I think feminism has opened up options for women to have other career choices and has re-instituted the idea that men and women are equal.(It is really hard to give feminists credit for anything though because if you give them an inch they'll take it a mile, and I don't mean equal the way they would mean equal). THAT being said, they don't stop at equality because they really desire superiority and the destruction of the chain of command that God established (Man, Wife, Children).... which all goes back to Genesis.
    Nevertheless, I'd rather see the vocational choice of the Amish versus the career-happy pressures of feminism. I think it is rare for a man or a woman to not have a need for a marriage relationship and I would rather see that form of society than one dominated by women.
    All in all, I think it has less to do with a "focus on marriage" and more to do with a focus on who is in control.
    But ....maybe that is the same thing?

  7. "I think it is rare for a man or a woman to not have a need for a marriage relationship and I would rather see that form of society than one dominated by women."

    Here here.

    Careful here though not to play into the feminist framing of history (not that you are). I think we can vastly overestimate how "dominating" men have been in history. "The hand that rocks the cradle rules the world" is true on all levels, and I think every married man of all times would say that his wife has just as much ability to dominate the marriage as he does. If momma aint happy aint nobody happy.

    Combine this with the fact that being a homemaker is unarguably the most influential profession for forming future generations, and I think it is pretty clear who has dominated human history.


  8. Ah, too true. =P That right there is what every feminist hates to hear. Sheesh..... we need to put that on a big banner flag and wave it around!! Literally the lie, that a woman would be more influential and happy if she goes to college and creates a career for herself instead of being a stay-at-home mother and a submissive wife, is so shallow that it's mind boggling to think that our society has accepted it as the norm.
    But try telling that to a bunch of bra burners... ;)

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  10. Hi Sarah Stanley,
    I want to gently caution you about IVF (or IVM from the article you link). These are gravely immoral procedures in which human beings are murdered on a massive scale. Fertilizing eggs outside of a womans body not only destroys the marital bond and is gravely disordered, but it results in many eggs being fertilized into embryos that will not live, many will not even be implanted back in the mother. I know it is strange our culture does these horific things, but if we stop and think about them, we don't have to go along with murder an gravely disordered activities like contraception, IVF, and abortion.

  11. One of the major factor that affecting IVF and IVMsuccess rate is Age. Lesser the age(30 - 40) maximum chances and maximum age(over 40) the lesser success rate. You have shared an informative post. Keep sharing and Thanks for sharing.

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