An interesting study on human behaviour in an MMO "suggests humans get more peaceful as the world ends": http://www.iflscience.com/editors-blog/video-game-study-suggests-humans-get-more-peaceful-as-the-world-ends/all/. Not a perfect study but still interesting.
Another, rather old, but still interesting blog on immersion in games. Rather lengthy but an interesting read, has a few interesting points: "Becoming immersed is partly that you really care about the outcome, for whatever reason, so you need some sort of emotional sensitivity to be able to connect to the game and want to have that connection." ..which suggests that players are actually highly imaginative and emotional. Read it here: https://www.theguardian.com/technology/gamesblog/2010/aug/10/games-science-of-immersion