Complete reversals (where N and S swap) happen every 300,000 years or so on average (varying a lot). The last reversal was actually 780,000 years ago, so I’m not sure what societal collapse this guy knows about from WAY into pre-history.

For general info, 780,000 years ago, there weren’t even modern humans. That’s firmly in Homo erectus times. It predates the oldest cave paintings by a factor of 16…