I see gender bias in this article. It mentions the influence of older WOMEN on society...but fails to mention the men! (Guess the brutes were too busy hunting bison to pass on knowledge at the hearth???)
They're just making a value judgement that teaching young mothers how to raise children is more important than teaching sons how to hunt and light their farts on fire.
Precisely chipping flint into arrowhead and spear points, the applied geology of how to find likely sources for flint, fire-starting techniques, the vagueries of animal migrations, how to tell when to expect the next salmon run, how to tell when some huge horned critter is about to charge -- all these branches of knowledge are insignificant compared to the proper way to burp a kid. </sarcasm>
Plus, having a few older guys around to protect the camp while they make more spearpoints and arrowheads would have been useful in reducing infant mortality (as well as women-mortality)