I think the over-confident people are not necessarily more sure of their abilities, but rather, less afraid of being wrong or making a mistake. Mistakes are jus

I think the over-confident people are not necessarily more sure of their abilities, but rather, less afraid of being wrong or making a mistake. Mistakes are just shrugged off, whereas for the under-confident, mistakes can be crippling and cause further under-confidence. Having a culture where it's ok to fail is very important for the under-confident to progress. Knowing that a wrong outcome is little more than an opportunity for learning can be incredibly empowering.