jg, ‘looking for the original research on CRM’ … I doubt that there is anything specific; thus there may be little scientific justification for CRM or the means of checking the effectiveness of training. Many references point back to NASA/NTSB.
However, the document
Crew Resource Management: An Introductory Handbook (FAA 1992), and its references (CRM aspects from the 80s, but supported with psychology) might help your quest.
Note that this differentiates between the philosophy and the application of CRM – an often overlooked and confusing aspect.
Also note the balance between the team and individual. It’s the individuals who require the skills. Most of these skills have a cognitive basis (page 10); thus we need to teach the skills of ‘thinking’ – if for no other reason, to avoid ‘the thinking/logic that got us into this trouble’.