Great study! Only gripe is that most trolling I get in online gaming is through voice chat. They also seem to troll me a tad bit more if I have a mic plugged in but I'm not talking. I suggest a re-run of this experiment recording the audio in case we get wildly different results. In a one-party consent state if you want to play it safe. ;)

I also think it will vary game by game. I don't play a lot of games. Most are shooters like Modern Warfare, Battlefield, and Mass Effect 3. Modern Warfare 2 and 3 on Xbox brought in more trolls in voice chat than all my others combined except maybe GTA V. In the last one, you play as a vicious thug causing problems for everyone around you. Them being pricks makes more sense. The difference in shooter games, though, was more interesting given it might reflect different sub-cultures in gaming. Specifically, MW is designed to appeal to largest number of people with lowest barrier to entry and patience required. Might self-select for higher percentage of jerks. Whereas, Battlefield 4 and Mass Effect 3 push people to work together more for best results.