The most common other arrangement in this society is serial monogamy (the original comment by marchenko means "stable marriage is the best", not "a bunch of marriages in a row are the best".)
In other cultures, the most common other arrangement is to give the child's mother's brother (uncle) all the rights and responsibilities that we give to the biological father/husband. The uncle rears the child, with the mother.
Marriage can exist in those societies but gives no rights over the child, and no or few responsibilities. (Might be time to consider offering this as an option for people in this society, at least.)
Children are little consoled by tax breaks, in my experience. Single mothers can't stay home on a tax break, since there's no income to get that break from.
Is being raised by ones uncle really more popular than being raised by ones grandparents, on a global scale? Somehow I doubt it. In many Asian countries being raised by grandparents is the norm but being raised by an uncle would be more of an uncommon arrangement.
I find that unlikely. I mean, what if there are no brothers? If, for sake of argument we say there are always exactly two children per family (approximation for stable population size and if some brothers die or move), there's about a 50:50 chance that a woman won't even have a brother to help raise the children.
Seems super unlikely to be the "most common" (by number of societies) arrangement when it only can work like 50% of the time in a society that DOES decide to do it. Was your Anthropology professor pulling your leg?
> If, for sake of argument we say there are always exactly two children per family (approximation for stable population size and if some brothers die or move),
Stable population size in any significant society is a very new thing, not historically common. Basing your assessment of historical likelihood on societies being assumed to have a trait that basically no premodern society did probably isn't reasonable.
I am from a part of the world - Kerala, India - where the matrilineal inheritance [1] was common up until about 50 years ago. This system worked as the GP described.
In other cultures, the most common other arrangement is to give the child's mother's brother (uncle) all the rights and responsibilities that we give to the biological father/husband. The uncle rears the child, with the mother. Marriage can exist in those societies but gives no rights over the child, and no or few responsibilities. (Might be time to consider offering this as an option for people in this society, at least.)
Children are little consoled by tax breaks, in my experience. Single mothers can't stay home on a tax break, since there's no income to get that break from.