Personality traits aside, Captains can build their own barriers to CRM by believing that they somehow possess more knowledge than the person in the right seat, therefore, that's what makes them a Captain.
In reality, that's 110% wrong.
The knowledge level requirements for a First Officer and a Captain at every airline I have worked at have been identical. Having given check rides to both seats, I held both seats to the same knowledge requirements. What makes the difference between the Captain and the First Officer is that, traditionally, the Captain should possess more experience to be able to wield that knowledge more effectively and take responsibility for it's application.
Now because of the absolute seniority train wreck that this industry has become, the most experience in the cockpit is not always weighted on the left seat. There are plenty of regional airlines out there who have FO's with thousands of hours of PIC in type pulling gear for brand new Captains. And every combination in the middle.
A good Captain will poll their crew to find out their experience so that they may use that experience effectively as situations warrant.
I learned a good lesson in this from a Captain at a previous airline. We were dispatched into an airport with a 7000' runway which was wet, and there was a 20kt. crosswind, and was only served by a VOR approach. To top it off, we had a FAA Inspector on the jumpseat. The Captain looked at me and said "Didn't you just say you went to recurrent last week?". I said yes, and he told me that If I felt comfortable, I should take the leg since I was probably more current on non-precision approach procedures than he was.
That really stuck with me. Here was a Captain, with many years flying wide-body aircraft, who recognized that because of this one specific situation, his First Officer was probably better suited to fly the leg than he was. It wasn't because I was smarter, or more experienced, but that the specifics of the day leaned towards the fact that my recency of experience with non-precision approaches would be of benefit. Where many, many Captains, possibly even myself before that day, would have just taken the leg because it seemed like the "normal" thing to do.
Those are the guys you try and model yourself after and who end up building the most CRM friendly environments in the flight deck.