> "Using inbreeding among European monarchs as an instrument shows that rulers with lower cognitive ability led to worse state performance and territorial losses from 10-18C. Rising parliamentary constraints limited rulers' impact."
I think "Statistically demonstrated that being stupid makes you a bad monarch" is a good fit in that vein :P Though I suppose it's a legitimately interesting question to what extent the monarch actually matters to their state's outcomes.
Biology: Does painting zebra stripes on cows reduce biting flies [yes]
Chemistry: Does Teflon™ as a food additive increase satiety/fullness [yes, allegedly safely?!]
Physics: Avoiding unpleasant spaghetti sauce texture
Engineering: Does using a ventilated UV shoe rack decrease odor [yes]
Aviation: Do intoxicated bats fly worse [yes]
Psychology: The effects of telling narcissists they're intelligent ["external feedback helped shape the subjects' perception of their own intelligence, regardless of the accuracy of that feedback" ; negative feedback is more impactful]
Nutrition: Is just cheese the favored pizza of reptiles [yes]
Pediatrics: Does garlic affect breast feeding [yes, babies will feed longer]
Literature: Does fingernail growth diminish as one ages [yes]
Peace: Does slight inebriation increase foreign language composition [yes]