The few correlations our feeble minds just happen to notice are not mystical decisions whereby nature slowly yields to the will of its creatures over many generations. Asking "why" is just anthropomorphizing for the sake of it.
This isn’t absolutely obvious, because reason has two different characteristic uses: asking agents their reasons for acting, and asking the reason some event happened. Philosophers have spent a lot of time asking how those two uses are related.
This is not an objective fact, it’s your interpretation. People are allowed to believe reality is divine and “anthropomorphism” is a strawman. Something you’re doing in your head and projecting onto others.
There is no individual selection either, by the way, that's another commmon misconception. You don't push out copies of yourself. There is only the selection of individual genes.
At a guess, just out of interest, how old do you reckon Paen and Tawan are here [1] as they drop a tree and process it to make Sago?
That's physically demanding work with a lot of prep (weaving mats, strainers etc).
Hunter/gathers/agrarians typically work until they drop and take care of children through extended overlapping family, not to mention taking children out to gather and dig from the get go from being carried before they can walk to having them follow along and help as soon as they are upright.
The 'nuclear' family structure is quite a recent development (in terms of human existence), and although far less common now, family structures typically included uncles and aunts and their children.
> It is a cohesive unit which ideally provides economic, social and psychological security to all its members. Adinlofu (2009) made mentioned that the extended family ensures procreation of children and provides for the early care and training of children. Degbey (2012) also added that this same family system defines “social and moral norms and safeguards both material and spiritual customs and traditions as well as providing a variety of role models preparing the way for adulthood”. Degbey (2012) emphasized that the dominance of the elders/aged has a relatively high degree of social control on the individual especially, the youth.
As for H-G family structure, I don't know much but most of what I know came from growing up in the Western Desert, Kimberley, and PNG talking to folk like the P-9 [1] and supply runs to Mike Alpers [2].
This, of course, is over 40 years back so <shrug>.
I never said they were disabled. I just meant, they'd be less motile and likely to work on clothing, crafts, homesteading, care of the children, maybe even cooking and leading the tribe/group in religion and/or study. Given they'd have more experience and wisdom, it makes sense the elder of the family structure would be more closer at home to lead the way.