The Tarzan Syndrome is when any newcomer arrives in a location or culture and has an overblown effect on the locals and their cultural interactions.
Origins – He [Chris Rock] decries the business’s preference for what he calls “Tarzan movies,” films in which a naive, poor black character is “discovered” by whites and finally wins over mainstream society with a combination of their help and his own street smarts. “People do what works and no black actor has ever worked better than Eddie Murphy,” Rock says. “So a movie like ‘Trading Places’ is great, when you do it on the highest level, with Eddie Murphy and Dan Aykroyd and John Landis at their peak. But if you do a cheap version of it, you really have something that’s not so cool. New York Daily News