In those daze

Tribal leaders made the final decision. Many of the earlier tribes forbade contact with outsiders. The belief was their mojo (lineage faith and protocols) in whatever belief serum, was weakened when scientific apparatus as simple as a watch undermined the focus of the continuity of the tribe. Like the first adult looking guy your daughter brings home, makes you want to serve brownies and shakes. Why that phobia of the intellect.

Because tribal leaders know how ruthless they have to be to instill obedience. They also know never trust. Even if they're worthy. Goodly dogs always lick the hand that feeds them before their hunger becomes insatiable.

Moral to the story. You have to be as ugly to survive the worst, your enemy perceives, you to be. The insatiable hunger to walk over the bodies of the innocent. Gives righteousness to stand, against murderous tyrants performing treason.