Do we space our children too closely in contemporary post-industrial society?

I recently posted something on this topic on Tiktok and it blew up the internet, so I guess people are interested! You can check that out here, or here if you prefer Instagram. 

Here’s the gist of it:

Most research suggests that in the Paleolithic, women would rarely have had children less than four years apart. This estimate comes from studies of contemporary hunter gatherer societies, which have consistently shown that interbirth intervals in these societies are much longer than they are in post-industrial societies. 

This is due to a few factors. First, hunter gatherer mothers breastfeed much more frequently and wean their children much later than we do in post-industrial societies. Some studies suggest that they put their babies to the breast every fifteen minutes during waking hours! We now know that the frequency of nipple stimulation, more than the duration of breastfeeding bouts, regulates reproductive hormones and suppresses ovulation. The other important factor is diet and exercise. Most hunter gatherer mothers are more nutritionally and metabolically stressed than mothers in post-industrial societies. As any athlete here knows, intense exercise and dieting both further suppress ovulation. This is why many mothers in post-industrial societies report getting their periods back or getting pregnant while still exclusively breastfeeding their children. It just don’t work like it used to. 

What’s most interesting to me, though, is not the mechanism by which ovulation is suppressed, but the fact that we clearly evolved to have children every 4 years, not every 2 (as is now the norm). In the US today, the mean interbirth interval is 24 months, and 30% of women have children less than 18 months apart! But we also have soaring rates of postpartum depression, often linked to parenting stress, and there is compelling evidence to suggest that a lot of mothers with no clinical diagnosis are still f***ing miserable. Is there a link?

I spaced my children exactly 2 years apart. My son was born on October 10, 2019 and my daughter was born on October 2, 2021. I was in a hurry, mostly because I hated my job and wanted to take advantage of the excellent maternity leave before quitting. But I also assumed that having children 2 years apart was the norm. Afterall, I am about 2 years older than my brother, and many of my peers were getting busy (I recently learned the term “rawdogging” thanks to a Brooklyn-based girlfriend) with a one-year-old in tow. Then there’s the argument that if you have them closer they will be better friends and play together. That felt like a pretty compelling value proposition at the time, as I was already very sick of building Lego towers with my son all day on weekends.

So how did it work out? My pregnancy and birth were smooth, but my daughter was born a full 1.5 pounds lighter than my son. After bringing her home, my son fell apart at the seams. We had done everything they said to do about preparing him for the arrival of his sister, but he just wasn’t ready. I had to lock myself in the bedroom in order to feed her and listen to him sobbing at the door. 3 days after she was born he came down with croup. I didn’t sleep for a week. Now that they are 2 and 4 they play together more but mostly their dynamic has been one of extreme jealousy, competition for my attention, and fighting over every household object they can get their hands on. 

I don’t regret having my two children because, like every mother, I love them both more than anything in this world and I cannot imagine my life without them. But strangely, I actually feel better knowing that my body really didn’t evolve to have children this closely-spaced, and with so little help from the community. Motherhood is hard no matter what, but in contemporary society we tend to add an extra serving of guilt. There were so many days in the year after my daughter was born that I felt like a failure and wondered why I couldn’t do the one thing that millions of women do every year and that mothers have been doing since the dawn of time. Well, it turns out, we haven’t been doing this since the dawn of time, at least not this way. Agriculture and industrialization profoundly altered the way we birth and raise babies, mostly to the detriment of women (more on this in future posts). 

I will end with this thought: if you are a mother of multiple young children doing most of the caregiving work alone and you are struggling, then please know that you are not a bad mother, there is nothing wrong with you, we simply did not evolve to raise children this way.

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