Svahn's dissertation looks at attitude changes via pervasive games. He self classifying some to those games are role-playing games.

Svahn, Persuasive pervasive game: The case of impacting energy consumption, http://www.diva-portal.org/smash/get/diva2:748740/FULLTEXT01.pdf

I do not know if that is something you are looking for, but there has been an article on moral decision making in Fallout (a video RPG).

Schulzke, Marcus: Moral decision making in fallout. Game Studies, 9(2), 2009

Although the journals website seems to be unavailable at the moment (and the journal itself is somehow shady).

(Game Studies is OK, not a predatory open access)

Good to know!

Brilliant, these are both very interesting and just about what I was looking for! Thank you!

My dissertation is on virtual emergency assistance in video games and its effect on violent and helping behavior. I used The Elder Scrolls Oblivion for this purpose. You can download the thesis for free (even here in ResearchGate), but sadly, it is only available in german. But there exist shortened descriptions of the study within an article about the CRTT and within a chapter about Modding (both also available in RG).

I haven't read it yet, but it is on my shelf:

Sarah Lynne Bowman. "The functions of role-playing games : how participants create community, solve problems and explore identity" McFarland, 2010.

May have something useful to your question.

Additionally, you will want to look into Jane Elliot and the Blue eyes Brown Eyes experiements.  They are used to demonstrate rascist attitudes.

Maybe the topic of group decision making and group problem solving will be helpful for you too. It seems that role playing games are based on that. It would be also interesting to see, if we consider agents in games, say your AI team in video games, like we consider the real life coworkers.