Answer to Question 1
Answer: Researchers such as Ekman and Friesen (1971) have conducted a series of cross-cultural studies, the most famous of which are the studies they conducted in an isolated part of New Guinea, where inhabitants had never seen Westerners. The New Guineans were able to match Western facial expressions with stories associated with various emotions. When the people in New Guinea posed facial expressions for photographs, Westerners could also recognize the emotions they portrayed. These studies provide convincing support for the assertion that there are a big six universally encoded and decoded facial expressions of emotions.
Answer to Question 2
Answer: In this case, smiling, which is a universal facial expression, will indicate happiness. The thumbs up or ok sign would be tricky because they are emblems and their use is more culturally specific.