If we go back to the original thread Barrelroll posted we are not, I believe talking about egotistical F/Os trying to strut their stuff, but the real (but thankfully infrequent) well meaning but interfering Capt who keeps up a running commentary of "left a bit, down a bit" imposing his style on the flight. We have a couple and as far as safety is concerned well I would agree that from the RH seat it is annoying irritating and sometimes darned dangerous, as one obediently follows what is prompted and "backseat drivers" are NOT in the loop so don't always make the right decision.
Behaviour wise it DOES show a lack of confidence, but it is in the Capt not the F/O who does not feel in control so has this burning need to impose the way he would fly the flight in order to feel comfortable.
Please let us dismiss the bleedin' obvious anecdotal stories that are clear safety issues, that's NOT a debate here that any sensible pilot would have.
But this subtle erosion of an F/Os esteem, confidence in making quite ordinary flying decisions is undermining and destructive. As a mature person, but newly into aviation, I handle this by looking at the prompt eg " you need to descend now, or turn now" carefully decide if it fits in with my situational planning and either comply or modify it "I'll take descent in 2 minutes / yes I think I'll turn now" rather than dumbly following orders. I think it is important to "own" the the decision yourself. The flight sector must be the responsibility of the PF although the Capt has the authority of the flight. CRM of course emphasises the process of decision making and is quite clear, but I wonder how many pilots take note. Let's be sure that flights are NOT on the solo Cpt standby copilot level.
Two captains who have this problem from different backgrounds, both very nice people indeed and didn't realise their interference. One is ex instructor and hasn't learned how to stop, so a lighthearted banter to him about "Is this lesson one or two on the C152?" caused a startled apology, he was quite shamefaced and we giggle about it now. The second is trickier as with some personal problems, single crew military mentality which he knows he slips into, and unfamiliarity on a new type gave him very low tolerance threshold of anyone he flew with. I tackled this by explaining in detail exactly how I planned to fly the sector (wx conditions etc) and before we got to (say) TOD or approach once we knew what was coming up I would then explain to him how I planned to fly it with options. The essence of achieving trust in the cockpit is being able to predict others behaviour so by letting him know what I was planning to do early seemed to defuse things. He then had the chance to put his views forward at a time when we could both consider them and stop this sudden "turn right now" "Call visual and if you can't see the airfield I'll take control because I have" (that was a beaut)
Going to the CP, passing control to the captain is all pretty destructive to everyone's morale, so anything you can think of to restore HIS confidence is going to be good. Now that all the line trainers will have completed their NOTECHS training by the end of March, hopefully they will start to pick up this problem on OPCs LPCs as they should, and gently but firmly get a more evenhanded performance from BOTH pilots in the cockpit