Thoughts sometimes emerge here that don’t get fleshed out until they appear on neoteny.org, after they’ve been gone over by an editor. Yesterday, reading Mothers and Others by Sarah Blaffer Hrdy, several poweful thoughts cruised through me.
The more older siblings a child has, engaging (and also perhaps tormenting) her, the better a child does on tests that require her to see the world the way someone else does. On closer examination, however, it turns out that it is not so much the number of siblings that matter as the fact that some are older. (p. 136)
Hrdy discusses the emergence of theory of mind in the context of human evolution driven by compassion with naturally selected communities of hominds displaying females working together to raise the kids. Hydy hypothesizes that far more children survived when caring for them was a community event. Theory of mind resulted from the exercise of compassion.
With her citation of studies that observe that first born children develop a less sophisticated theory of mind, it becomes a possiblity that the reason autistics congregate in the first born and those born to older mothers is because first borns aren’t introduced to a caring environment with multiple principles while later born gestate in higher testosterone wombs.
This feels significant. Autism may be partly a result of children raised in environments not natural to our species, homes with only one principle female. This would suggest that older mothers with only one child should have significantly higher percentages of autism. Recent studies calling attention to wealthier parents having higher percentages of autistic children may acutually be noting the tendency of wealther parents to have only one child when the parents are older.