Couldn't you still study populations with more or less plastic, even if "zero plastic" cant be found? Or is the amount of it more or less even across groups?
Throwing in my $0.02, a correlation study is technically an option, where you look at differences as microplastics increase in concentration. But. my instinct is you would see some really unfortunate covariance - that is, another variable that increases (or decreases) at the same time as microplastics and is known to impact your variable of interest, e.g. socioeconomic status.
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.
I hate to break this to you but this shit level of empathy has been with humans for thousands of years. This is not a new phenomenon. It's not caused by microplastics.
What is new is empowering those without empathy to decide world leaders that have an obscene amount of power. That's a relatively new development for humanity.
Honestly, that's been around forever too, whether by votes or force of arms... Come to think of it, it's mostly the force of wealth and always has been.
Regardless of how shitty the DNC is, it seems to defy logic that anyone could support Trump, and yet half of the US does. Because of that, I can see why someone might start thinking there must be some sort of external cause or something.
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”.