But as the New York Times recently explained at length, Bryan Pesta deserved to be fired from his tenured professorship because he used taxpayer-paid data to find truths that the New York Times wishes weren't true.
My dissertation advisor Lee Willerman used the data for a couple of his papers. I think Eric Turkheimer used it in his dissertation.
One thing Lee told me he found but never published was that c-sectioned kids had higher IQs. Pretty sure he’d have thought to control for mothers’ IQ. He thought it might represent a difference in birth canal trauma.
I went and looked for the WISC FSIQ. In the basic OLS specification that just controls for sex, race, birth order, and maternal age, I got -1.29 IQ points for a C-section (p = 0.002). With a control for SES in the form of education years and the SEI score, that went to -0.92 (p = 0.018). In the mother FE that just controls for sex and birth order, the result was +1.53 (p = 0.12).
In an OLS with demographics, SES, birth weight, gestational age, and Apgar total, I get -0.88 (p = 0.030). Mother FE with birth weight is +1.51 (p = 0.12) and with added gestational age and Apgar total, it's +0.77 (p = 0.47).
So, I'd say, not much evidence for C-section benefits here.
Incidentally, I also checked out whether head circumference predicted being a C-section birth in this cohort, and the answer is no! Head circumference at birth was 33.66 cm for vaginal births and 33.60 for C-sections and there seems to be an elevated risk of C-section for both extremely small- and extremely large-headed babies. Within families with discordant births, there's no gap either, and power is too low to detect if there's a difference between extremes.
This is a good cohort to test this in because, in the '60s, C-sections were driven by obstetric emergencies like malpresentation, fetal distress, prior C-section, etc., rather than size measures per se.
It's the same dynamic as with breast feeding. High IQ/High-SES moms are risk-averse and also don't have a problem paying for c-section. Which of course colours the results if one doesn't correct for maternal IQ.
Slightly off topic, but what was your process of actually finding, scanning, and digitizing the microfiche? I'm sure this could be done with other datasets, very cool work.
The people who scanned it in did all the physical work of moving all the microfiche into the scanners and uploading it. I took what they uploaded in various formats, aligned it, OCR'd it, and cleaned it up.
Wait, what are the implications of that graph about IQ and family size? Does it mean that the birth order effect isn't actually real and it is just confounded by the age at the mother's last birth? Is this also true for the "birth order causes homosexuality" claim?
But as the New York Times recently explained at length, Bryan Pesta deserved to be fired from his tenured professorship because he used taxpayer-paid data to find truths that the New York Times wishes weren't true.
It's unfortunate how biased and unscholarly journalists have turned out to be.
My dissertation advisor Lee Willerman used the data for a couple of his papers. I think Eric Turkheimer used it in his dissertation.
One thing Lee told me he found but never published was that c-sectioned kids had higher IQs. Pretty sure he’d have thought to control for mothers’ IQ. He thought it might represent a difference in birth canal trauma.
Good question!
I went and looked for the WISC FSIQ. In the basic OLS specification that just controls for sex, race, birth order, and maternal age, I got -1.29 IQ points for a C-section (p = 0.002). With a control for SES in the form of education years and the SEI score, that went to -0.92 (p = 0.018). In the mother FE that just controls for sex and birth order, the result was +1.53 (p = 0.12).
In an OLS with demographics, SES, birth weight, gestational age, and Apgar total, I get -0.88 (p = 0.030). Mother FE with birth weight is +1.51 (p = 0.12) and with added gestational age and Apgar total, it's +0.77 (p = 0.47).
So, I'd say, not much evidence for C-section benefits here.
Alas!
Incidentally, I also checked out whether head circumference predicted being a C-section birth in this cohort, and the answer is no! Head circumference at birth was 33.66 cm for vaginal births and 33.60 for C-sections and there seems to be an elevated risk of C-section for both extremely small- and extremely large-headed babies. Within families with discordant births, there's no gap either, and power is too low to detect if there's a difference between extremes.
This is a good cohort to test this in because, in the '60s, C-sections were driven by obstetric emergencies like malpresentation, fetal distress, prior C-section, etc., rather than size measures per se.
It's the same dynamic as with breast feeding. High IQ/High-SES moms are risk-averse and also don't have a problem paying for c-section. Which of course colours the results if one doesn't correct for maternal IQ.
Slightly off topic, but what was your process of actually finding, scanning, and digitizing the microfiche? I'm sure this could be done with other datasets, very cool work.
The people who scanned it in did all the physical work of moving all the microfiche into the scanners and uploading it. I took what they uploaded in various formats, aligned it, OCR'd it, and cleaned it up.
Wait, what are the implications of that graph about IQ and family size? Does it mean that the birth order effect isn't actually real and it is just confounded by the age at the mother's last birth? Is this also true for the "birth order causes homosexuality" claim?
The birth order effect is real and separate, going beyond family size, which doesn't actually seem to have much of an effect.