People within each ethnic group often carry themselves in a similar way. The stride, posture, eye contact, smiling impulse and personal space expectations come together, creating a shared climate or mood. Some cultures are more demonstrative; others are more reserved. Some say Americans smile too much – that it feels inauthentic. But, because the United States has more diversity than many other countries, smiling has developed as an impulse to show good intentions. Norms are just how we do things around here.