“When he put lonely people into brain-scanning machines, he noticed something. They would spot potential threats within 150 milliseconds, while it took socially connected people twice as long, 300 milliseconds, to notice the same threat. What was happening? Protracted loneliness causes you to shut down socially, and to be more suspicious of any social contact, he found. You become hypervigilant. You start to be more likely to take offense where none was intended, and to be afraid of strangers. You start to be afraid of the very thing you need most. John calls this a “snowball” effect, as disconnection spirals into more disconnection.”