From Ellen Rohr, one of my favorite business writers:
It comes down to manners. If mama taught you good manners while you were growing up, you are at a decided advantage in 
relationships – personally, in the workplace and in your community. Good manners are the little things that we do for each other to grease the skids of communication. Good manners help us respect the increasingly smaller distance between people on our planet.
Say "please" and "thank you." Even to family members. Hold the door. Keep the door from slamming shut on the person walking in behind you. Offer your seat to someone who needs it more. Don't yell at people. It's rude and disrespectful. Once voices are raised, communication is reduced.
You might not be offended by swearing, but in a crowd of two or more, someone else may be. Why risk it?
Criticize in private. That said, praise in public, praise in private – catch people doing things right all day. And brag on them. It's good manners.
