Pierre Guillaume Frédéric le Play argued that France's early fertility decline was driven by its inheritance reforms, where estates had to be split up equally to all of the kids, including the girls.
There's likely something to this!🧵
For reference, the French Revolution ushered in a number of egalitarian laws.
A major example of these had to do with inheritance, and in particular with partibility.
In some areas of France, there was partible inheritance, and in others, it was impartible.
Partible inheritance refers to inheritance spread among all of a person's heirs, sometimes including girls, sometimes not.
Impartible inheritance on the other hands refers to the situation where the head of an estate can nominate a particular heir to get all or a select portion.
Pierre Guillaume Frédéric le Play was an early economist, engineer, and sociologist born in 1806, who looked at trends in France's fertility.
He proposed that cutting up estates weakened family solidarity and made children into 'costs' on the estate, thus lowering fertility.
To get at this, researchers put together a shapefile for the 435 judicial districts within which different inheritance rules historically applied.
These have to do with (A) customary laws and written laws and (B) inheritance systems across partibility and women's inclusion.
The data on inheritance systems and laws was paired with historical fertility data from two different databases.
Together, this makes it possible to compare fertility before and after the inheritance law changes made regions more legally similar.
If we look at trends in fertility over time comparing regions that impartible versus partible inheritance, the ones with impartible inheritance start off with higher fertility, but after the reforms, rapidly converge.
Looking at women before before or after the reforms, we see that fertility substantially falls for affected cohorts, and the average effect is substantial.
Using different data, the results are replicated.
Here, a regression discontinuity design with borders between areas with different pre-reform inheritance rules shows that, prior to the reforms, inegalitarian practices were associated with fertility.
And after, this goes away.
It seems Le Play was correct! Inheritance practices definitely impact fertility.
But, while this is an explanatory factor for some of France's decline and the convergence across its regions, the decline of religion is likely more responsible for the decline shared across them.
You know how most books on Amazon are AI slop now? If you didn't, look at the publication numbers.
Compare those to the proportion Pangram flags as AI-generated. It's fully aligned with the implied numbers based on the rise over 2022 publication levels!
Similarly, the rise of pro se litigants has come with a rise in case filings detected as being AI-generated, and with virtually zero false-positives before AI was around.
In terms of their employment, religion, and sex, people who joined the Nazi party started off incredibly distinct from the people in their communities.
It's only near the end of WWII when they started resembling everyday Germans.
Early on, a lot of this dissimilarity is due to hysteresis.
Even as the party was growing, people were selectively recruited because they were often recruited by their out-of-place friends, and they were themselves out-of-place.
It took huge growth to break that.
And you can see the decline of fervor based on the decline of Nazi imagery in people's portraits.
And while this is observed by-and-large, it's not observed among the SS, who had a consistently higher rate of symbolic fanaticism.
I simulated 100,000 people to show how often people are "thrice-exceptional": Smart, stable, and exceptionally hard-working.
I've highlighted these people in red in this chart:
If you reorient the chart to a bird's eye view, it looks like this:
In short, there are not many people who are thrice-exceptional, in the sense of being at least +2 standard deviations in conscientiousness, emotional stability (i.e., inverse neuroticism), and intelligence.
To replicate this, use 42 as the seed and assume linearity and normality
The decline of trust is something worth caring about, and reversing it is something worth doing.
We should not have to live constantly wondering if we're being lied to or scammed. Trust should be possible again.
I don't know how we go about regaining trust and promoting trustworthiness in society.
It feels like there's an immense level of toleration of untrustworthy behavior from everyone: scams are openly funded; academics congratulate their fraudster peers; all content is now slop.
What China's doing—corruption crackdowns and arresting fraudsters—seems laudable, and I think the U.S. and other Western nations should follow suit.
Fraud leads to so many lives being lost and so much progress being halted or delayed.
British fertility abruptly fell after one important court case: the Bradlaugh-Besant trial🧵
You can see its impact very visibly on this chart:
The trial involved Annie Besant (left) and Charles Bradlaugh (right).
These two were atheists—a scandalous position at the time!—and they wanted to promote free-thinking about practically everything that upset the puritanical society of their time.
They were on trial because they tried to sell a book entitled Fruits of Philosophy.
This was an American guide to tons of different aspects of family planning, and included birth control methods, some of which worked, others which did not.
One of the really interesting studies on the psychiatric effects of maltreatment is Danese and Widom's from Nat. Hum. Behavior a few years ago.
They found that only subjective (S), rather than objective (O) maltreatment predicted actually having a mental disorder.
Phrased differently, if people subjectively believed they were abused, that predicted poor mental health, but objectively recorded maltreatment only predicted it if there was also a subjective report.
Some people might 'simply' be more resilient than others.
I think this finding makes sense.
Consider the level of agreement between prospective (P-R) and retrospective (R-P) reports of childhood maltreatment.
A slim majority of people recorded being mistreated later report that they were mistreated when asked to recall.