"Over the past few years, he and others have found that medium-size groups of animals or humans are optimal for decision-making"

As someone intrigued by the mechanics of politics, this really struck home. Autocracies are bad for a variety of reasons - and so too are true democracies (where everybody can vote on many issues...see the CA ballot initiative chaos in public policy).

Representative democracy strikes this "goldilocks" balance with fewer actors than full representation, but far more than a restrictive oligarchy.