"...downvotes...significantly reduce dopamine levels not only for those who receive them but also for everyone else who observe the drama."
Fairness and equity are fundamental in all higher vertebrates. We've all seen the videos of monkeys outraged when they get cucumber bits and their neighbor gets grapes. Dogs will fight to the death over insignificant tidbits, because it's not the tidbit that matters, it's the social approval they signify that does.
Hive is doing that all wrong with DV's.
I've pointed it out before, but DV's aren't the opposite of upvotes. The opposite of an upvote is no vote. DV's are taxes. Nobody likes paying taxes, because taxes are theft. DV's work to prevent spam, scams, and plagiarism because they're onerous. Applying them to opinionated speech is asinine and kills the Hive.