Most people hesitate to say hello – or smile – when they see someone unfamiliar. Why do we hesitate to greet a stranger?

If you greet a stranger with a smile or a ‘hello’, there’s a 98% chance that she or he will smile back and say hello. Both of you will probably feel better having exchanged smiles. And who knows, it might open a surprise door.

But there’s a 2% chance that the person will snub you. Not smile back. Look the other way. Make you feel sheepish. Look stupid even. That’s only a 2% probability of that happening – but the fear of looking stupid, stops us from saying hello, and smiling.