I’ve written about the implications of highly fertile, highly religious groups such as the Amish and Haredi Jewish community before. While Latter-day Saint fertility is higher than average, it’s not even close to those levels, and probably won’t ever be unless we revert back to Haredi-levels of communal insularity (or reinstate polygamy), which is a move I don’t think we should do for various reasons. Still, in some ways it’s inspiring seeing some groups buck the trend, and future, perhaps qualitative, work may shed some light on how to maintain large family sizes without having to go full Amish, who knows.

Using IPUMS Census data, I pulled the number of own children in a home, a measure that is often used as a good-enough proxy for children ever born at that age, for people between the ages of 36-50. I divided the trend lines out by language: Spanish and English, to get a more typical swath of the population, along with Yiddish speaking and Pennsylvania Dutch speaking.

The latter two languages are German-based. Yiddish is largely spoken by the Haredi community, and Pennsylvania Dutch is largely spoken by the Amish and their cousin faiths, so in the absence of a religion question in the US Census, taking language spoken at home can kind of get at some religious and ethnic communities, but it’s obviously not perfect, since the kind of Pennsylvania Dutch and Yiddish speakers who respond to US Census survey are probably more “liberal.” Also, Census data can get complex, so if I was submitting this for peer review I’d put a lot more time into those technicalities, but for our bottom-line purposes these simple estimates should work.

As seen, the Yiddish and PA Dutch languages jump around a little more, as they only have about several hundred per year in the target age demographic, but there is a clear upwards trend in family size across time, suggesting that family sizes are increasing while, as a point of comparison, the typical American’s is obviously decreasing.

One caveat, this may be an artifact of the decline in non-Haredi Yiddish speaking households or non-religious Pennsylvania Dutch households. As fewer non-Haredi or non-Amish speak these languages, the ones that still do are the more religious, more fertile groups, but I don’t have enough insider information on these linguistic communities to know how feasible this explanation is. I bounced these numbers off of a Jewish Studies colleague who does research with this community, and he said they passed the smell test, and were probably attributable to both the relative decline of non-Hasidic (both Haredi and non-Haredi) Yiddish speakers along with the increase in family sizes.

Whatever the case with the trendline, it is clear that these groups have sky-high fertility in official government data in the year 2025. There are some newer property developments that are almost exclusively Haredi, and it will be interesting to watch them as more census data comes in and we get a trend line to see how long they can maintain large family sizes in the face of modernity.

As for us, again I think the best we can hope for is maybe slightly more than what we’re pulling now. If we really dialed up the pronatalist rhetoric, which I doubt will happen given the sensitivities involved (plus I think people tend to exaggerate the extent to which General Conference talks influence people’s personal day-to-day lives and lifestyle decisions), maybe we could hit 3.5 or so.