Geary - what would prove to you that "social media acts as a radicalising force for extremist viewpoints"? It seems well established to me, but you describe it as unproven, so I'm asking what would prove it for you?

I haven't heard of Parasite Stress. I'm not sure comparing US federal administrations will be productive here, but I can say that I found/find "zero tolerance" child-separation policies truly despicable.