MDMA releases the chemical oxytocin, which our bodies naturally produce. The chemical causes animals to fiercely love their own, but also protect them from others — which can mean a disdain for outsiders may actually increase.
I would have to see more data or examples to take this last clause as real. It sounds like some off-the-cuff dualist BS conjecturing. I can’t imagine oxytocin increasing disdain of outsiders just because it induces the opposite feelings toward your in-group.
Neuroscientist here. Neuropeptides always have dozens of different uses, and oxytocin is no exception. The idea that it is a “love hormone” is a simplification for the lay person.
Sure, here’s a review article: https://www.sciencedirect.com/science/article/pii/S0018506X11002868
