Rat5 I agree with the posters who mentioned sim training/ briefing. If it is made clear that it is a low G manoeuvre with 5 seconds to react prior to the exercise then there is less chance of pilots over reacting. I have had a descend now RA at 3000ft in the aircraft with ATC telling us " negative maintain 3000ft" . I was an FO and PF and the Capt transmitted " negative TCAS RA" . We followed it to anout 2500ft and then after returning to 3000ft got a frequency change, the next controller asked us if it was a TA or an RA. We informed him RA. It was very simple and calm for us but I imagine if we hadn't had specific training in ignoring ATC in this situation it may have been a difficult decision to ignore them. It was actually a bit surreal as it was so much like the training we had recieved. It is also valuable to do them above FL 350 in the sim to demonstrate to the crew that the control inputs are very small and controlled.