Survival skills are all negative by necessity but for the most part no longer necessary. But you are right we do tend to think negative especially in high stress situations. Something you don't notice though is the increased brain activity that negative sets off. To be sure in a negative situation the brain checks associated memory. This associated memory says, this is what happened in other situations. Therefore if associated memory is positive then the original thought will change to that too because it will seem appropriate to change. In effect shortening anxious moments till they no longer register or at least don't stimulate others. But if associated memory is negative the original thought will stay negative. It can even change a positive thought to negative.
The exercise u suggested is good for build of positiveness.The automatic reaction of mind is to think of negative.For every negative statement there occurs a positive statement which is a fact.The practice should be such that positiveness should flow automatically.This is a difficult task yet achievable.My negative thought replacement is just 30% at present.
By regular positive practices it can be increased to a considerable extent,I believe.
And why would it not be? What else are they than the replaying of memories and you have billions of memories to choose from. What you choose depends on what is important and how important it is is attitude.
Pick a quiet half hour and think about nothing but a pleasant time from your child hood, it has to be far enough back that today can't influence it. For that half hour you want nothing but good thoughts. If you keep getting bad thoughts then forget about the rest of this exercise. If you have had a half hour of pleasant thoughts then think the next half hour about things that could go wrong. If you can do that then think a bad thought and change it. What this does is prove that you have more than one thought with each situation and you have choice. If you look close you will see you have lots of choices for each situation. If you can't do this then you have too negative of an attitude to access positive thoughts and you have to fix it first.
