Heinlein was partly right

[nancylebov]

Pioneers have more children.

Heinlein's stuff about people wanting to maximize their number of children never sounded right to me in general, but I thought it might be true of pioneers.

The study, published November 4 in Science, analyzed the genealogies of settlers in Canada's Charlevoix Saguenay Lac-Saint-Jean region, northeast of Quebec. Since the colony's initiation in 1608, it underwent several waves of geographic expansion. The researchers, led by population geneticist Laurent Excoffier from the University of Montreal, looked at the colony's marriage and birth records between 1686 and 1960. The analysis found that families living on the edges of the expansions had 20 percent more children than families living at the core of the settlement. They also married one year earlier, on average, and contributed up to four times more genes to the region's current population.

I'm surprised, though, that the effect isn't huge in the short run-- only 20% more children. It's not something like having seven kids instead of four.

Link thanks to Marginal Revolution.

Comments

[twistedchick]

Statistics are estimates, and often in practice turn out to be more like averages. Twenty percent could work out to one more child in some families and five more in others. Or serial marriages in which each wife has several. Or one family that has two children and takes in six orphans, while another has 19 children. Earlier marriages in areas without contraception tend to produce more children, also. Someone who marries at 13 or 14 is likely to be fertile for the same 40+ years as someone who marries at 25 -- but may have four children before 25.

[wcg.livejournal.com]

I'll dig into the data, but I'm wondering if they address infant mortality. My Canadian ancestors had lots of kids, and also buried most of them within three years of their birth. Infancy was tough in the farm country of Ontario back in the mid-19th century.

[nancylebov.livejournal.com]

Was it a whole lot better in longer-settled areas? It well may have been, I just don't know.

[nellorat.livejournal.com]

Based on generalities I know, my guess is no. On the one hand, no doctors on the frontier. However, until the early 20th century, doctors really couldn't do all that much. And on the other hand, infectious disease, the main cause of child mortality, was much more prevalent in areas with more people.

[avram]

Do they have more kids because they're pioneers, or do they become pioneers because they want to have more kids?

[dr-zrfq.livejournal.com]

What I'm wondering is, what is the difference in birthrate between [a] pioneers (those living on the edges of expansions), [b] non-pioneer FARMERS, and [c] city folk, particularly better-off city folk.

[houseboatonstyx.livejournal.com]

Maybe there's nothing else to do at night?

[dcseain.livejournal.com]

The largest generations of my family happened in mostly pre-mechanized farming days, so that makes sense to me. Not much else to do, and free labor.

[richardthinks.livejournal.com]

Adam Smith noticed this in the 1780s and ascribed it to an expanding market for labour and according wealth for the labouring classes: he figured people in long settled areas wouldn't be able to support extra kids so their families wouldn't grow, while frontiers offered opportunities for labour expansion so families were larger.

I'm not sure how he figured the biology would follow his economic imperatives.

[nancylebov.livejournal.com]

More food so that more children survive?

[richardthinks.livejournal.com]

That would make sense, but IIRC he talked about them wanting more kids...