yeah, it changes their brain in ways that are driven by their work. their hormones and dna are made the way they are for that purpose.

what do you think the deal was before all this authoritarian religionism?

the boys balls drop, they go walkabout, they survive on their own initiative, maybe they gave them one sharp flint to make everything they need. they had to feed themselves, they had to shelter themselves, and secure themselves against the predators.

the girls start bleeding, they go to the women's camp. they are taught the secret women's business. they learn about medicine and herbs and food and cooking and how to keep track of the children and make sure they are safe.

after their training, they return to the general population, and events are held that are about matchmaking them. these rituals are extremely sexual. there is sniffing, there is touch, there is supervision only to the extent that nobody is toxic. toxic ones are exiled. the freaks that don't want this game, have to go and live at the borders of the village as seers and shamans whose internal study makes them valuable, but makes them impossible to fit into the average, they are threatening, strange and their intelligence makes them unsuitable for the general village business, but everyone depends on their specialisations.

the moment they come of age, they are prepared for what they are coded to do.

there is no mismatching calendars, the moon and the sun and the weather are the authority about when what happens. the menses, the sexual urge, the urge to fight, are all directed to their best productive outcome.

modernity and technology don't change the equation. what defines the modern age is the abstraction of power and the normalization of the most toxic becoming the rulers, and maintaining a hierarchy of violence to milk the general population. so they interfere with every natural process that makes the tribes coherent.