That's very fair. Anecdotally my Japan-living friends speculate it is a mix of both the (positive) effect you suggest and confessions manufactured under duress.

That's very fair. Anecdotally my Japan-living friends speculate it is a mix of both the (positive) effect you suggest and confessions manufactured under duress. During my travels I was advised to be particularly cautious about treating police courteously and following rules to the letter because getting arrested is a much bigger deal than elsewhere.