> The transition from one to two kids is a qualitative change for the kid because it means going from no siblings to siblings. That transitively makes it somewh

> The transition from one to two kids is a qualitative change for the kid because it means going from no siblings to siblings. That transitively makes it somewhat of a qualitative change for parents. It means the kids always have a playmate and someone their age on vacations. ... Or fightmates, as my mother herself warned me. :-)