2. Teach them to be polite.

Teaching kids to say "please" when they ask for something can reinforce their tendency to be polite, which makes them more persuasive when they're older. Teaching them to say "thank you" habitually encourages gratitude, which stimulates happiness and makes stress easier to deal with.

And teaching them to say "you're welcome" reinforces confidence by emphasizing that the things they do for others are worthy of thanks. (This is especially true when you juxtapose "you're welcome" with other things people say in response to "thank you," like "no worries!" or "no problem!")