Interesting piece here from Dave MacLeod where he argues that positive thinking is not necessary:
http://onlineclimbingcoach.blogspot.com/2015/06/positive-thinking-is-not-ne...
Excerpt:
"The positive thinking paradigm, in summary, suggests that by using positive visualisation, we create an image that we are more likely to live up to in the real event. Unfortunately the research shows this approach is ineffective. Positive thinking appears to reduce motivation and self discipline. Moreover, it tends to kill the critical thinking that underpins learning of complex skills. A practical example of this is when coaching climbers to overcome fear of the most basic form of climbing fall - falling onto mats at an indoor bouldering wall. Unless you also consider what a badly executed fall looks like, how can you even visualise ‘good’ falling and landing technique. If positive thinking allows you to believe the fall will be fine when you jump for the last hold, the fall, should you miss, is that much more undermining for the confidence since you did not expect it. In my own preparation for climbing situations of all types, I have found that I take care to examine the negative outcomes as well as the positive. I look for the problems and the weaknesses. But all this focus on the negative does not mean that I think or talk myself into failure. Quite the opposite. I deal with the problems at the time when they should be dealt with - in the preparation stage."