You need to ask yourself, ‘how am I building the self-confidence of the people around me?’
A multiplier helps others find their area of strength and encourages/challenges them to greater heights than they themselves felt possible. They make others feel brilliant.
A diminisher sucks energy out of a room by having to be the smartest person there. They make others feel dumb.
And if you think that self-confidence doesn’t affect how people perform, check out Tiger Woods. He went from being a consistent winner to being a consistent loser all based on how his perception of himself changed.
Eroding someone’s self-confidence is a very expensive venture.