The fraternal birth order effect and its replication crisis
Williamson explains the birth order effect, where each older brother from the same mother raises the chance a subsequent son is gay, possibly via immune-system mediation in the womb, with miscarriages counting too. He notes newer data from Jakob Fort and colleagues suggesting the effect extends to lesbians, before flagging that the whole finding has hit a replication crisis and may need updating.
- More older brothers correlated with higher likelihood of a son being gay
- Proposed maternal immune-system mediation in the womb
- Miscarriages may also count toward the effect
- Newer data suggested the effect exists for lesbians too
- The finding is now in a replication crisis and may not hold
“Maybe I've not fed you false information, I've just fed you information that might need updating.”