Forget Russia, the biggest conspiracy theory now among us is the "school-to-prison pipeline" and "the new Jim Crow." That literally involves tens of thousands within our justice system. Others include belief in coordinated voter intimidation by the GOP/Trump at the polls, Monsanto and other corporate conspiracy theories, the various left-wing theories about Trump and COVID, from him faking contraction, to the idea that he intentionally contracted it. Don't forget the conspiracy theories within the BDI movement that assert that America's cops are trained in methods of oppressing blacks from the IDF.
Conspiratorial thinking is primarily a function of radicalistic political ideologies, not education. As the highly educated have become more radical politically, they have embraced more conspiratorial thinking.
As for your premise that more education equates to higher intelligence, that is generally true, but there are many exceptions. Some, just down the hall.