Earlier quoted context omitted.
It's interesting that folding your arms when faced with a difficult problem can make you more persevering. http://www2.canada.com/components/print.aspx?id=fb05abc6-149...
When facing a difficult problem and trying to project confidence, I prefer sitting astride a rearing horse, brandishing a sabre. The body language mirroring and influence thing has a comprehensive theory on using it to your advantage: Neuro-Linguistic Programming. Unfortunately, it has little experimental support, but it's still trendy with the management and life coaches--which doesn't necessarily make it not true;…
This wasn't about trying to project confidence. It was a study that looked at students working alone. I find I will sometimes cross my arms if I am thinking hard about a problem. What was interesting was that the study provided some evidence that it would help me to persevere.