I mean, sure. But if the study is only on assholes, then it won't tell you how many non-asshole parents have asshole lids. That's one side of the coin gone. And if this study doesn't control for nurture, then really all it can tell you is what percentage of the time the studied assholes have asshole kids, without even addressing why. Sounds like the sturdy has scoped itself out of being able to produce very profound results, why wouldn't its conclusion be trivial?