Living Worlds

Research · Lifetimes · Oct 6, 2026

Siblings, from partnerships that make fathers

Not metthree survey years, 2000, 2010 and 2018

Improved A later registered study met the bar: Siblings on the mother's side, in four years never read.

The test at a glance

What it tests
Accuracy against reality: how many brothers and sisters people report.
Data
General Social Survey, US-born respondents, 18 cells in 2000, 2010 and 2018.
Held out
The sibling answers of those three years.
Compared against
Gemini 3.8 Flash answering from what it has read.
Bar
Lower mean error over the 18 cells than the text model.
Result
0.49 against 0.41: not met.

Across three survey years, the lived population counted children ever had more closely than a text model (0.12 against 0.15) and came closer on siblings in 2010 and 2018, but pooled it missed siblings by 0.49 against the model's 0.41, overcounting people then 35 to 44 in 2000. Counting the mother's side alone missed by 0.36. Registered before scoring, on 2000, 2010 and 2018, never read for siblings.

Protocol, result and scorer

Protocol Scorer Result

Next

The mother's side, same engine, on four survey years never read: met (the result).

Lifetimes

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