[jrimbault]

Last year I read HN many times a day and often staying awake two days in a row, I've observed that phenomenon you're describing. And from what I've observed, that crowd is different (and stonger) when the Americas are awake than when Europe is awake.

There seemed to be less downvoting around 10am GMT than at 6pm GMT.

[yorwba]

I think it's just that less voting in general happens when America is asleep. At least that's the conclusion I drew from my unhealthy sleeping habits.