Our older, “normal” child is male. Then our autistic son, and our autistic daughter. Dunno what happened between children #2 and #3.
I for one ‘nuked’ the baby bottle and food on plastic plates for older sibling that ‘may’ have affected 19 month old younger bro while he was developing if u follow that article’s theme. That is the closest I have come to an answer as the boys are total opposites...like the movie TWINS with Arnold S. Much older siblings are fine too - but that was before nuking plastics were used as much.