I don’t think microplastics are having that effect.
It could just as likely be the decrease in airborne Lead following the removal of Lead Paint and TetraEthyl Lead in Petrol has caused people to be much more aggressive.
They still have the brain damage from growing up breathing in heavy metals, but no longer have the soporific effect of heavy metals.
US self-entitlement.
the land of the free has always had a “more important than every other country” mindset which has infected their citizens with the same selfish mindset.
McCarthyism and subsequent witch-hunts have resulted in such an anti-socialist zeitgeist that it has morphed into an anti-social zeitgeist where any empathy for any other person is seen not only as a weakness, but as also being “Un-murikan”.