In 2015, a group of researchers of the University of Wisconsin-Madison formulated their own theory on why, somewhere, people are more inclined to smile. The answer is to be found in immigration and multiculturalism. The United States and Canada have a diverse population, composed by 83 and 63 different national or ethnic groups each. Non verbal communication played a central role in socializing and building trustful relationships among communities. This is not needed in more uniform countries…