Role-Playing Game Studies: Transmedia Foundations [book release]

Deterding, Sebastian, and José Zagal, eds. Role-Playing Game Studies: Transmedia Foundations. London: Routledge, 2018.

A new multidisciplinary academic book on TRPG. The editors gathered most of the renown authors in the field to write chapters on TRPG with different disciplinary angles.
Without conflict of interest, I suggest you ask your college or university librarian to buy it. I did.

Bowman, Sarah Lynne, and Andreas Lieberoth. “Psychology and Role-Playing Games.” In Role-Playing Game Studies: Transmedia Foundations, edited by Sebastian Deterding and José P. Zagal. London: Routledge, 2018.

A very clear, evidence-based and comprehensive chapter about everything you wanted to know about TRPG and psychology. It is partially readable via Google Books.