#49: Must. Not. Smile!
Growing up in America, this whole concept confuses me. Apparently, in some cultures, people who smile are considered unintelligent or untrustworthy. The stoic look is the only way to assure everyone you mean business and know what you’re talking about. Even cracking a smile in public is off-limits.
There have been many studies done on why this is the case, including one that took pictures of people smiling and frowning and then asked thousands of participants to rate their intelligence and reliability. The more stable the country’s public programs, the more likely they would appreciate a smile. I think that says a lot about humanity.