They usually respond to a strong alpha person and hence the myth. Chows are devoted to their family. A properly bred Chow will stand in the face of danger to protect it's family. Chows do not bite any more than any other breed, especially compared to lap dogs, who bite all the time, but without consequence, so people think that doesn't count. But when Chows do bite they can be fearsome and this makes headlines.
Chows are stubborn.
Chows are not kissy lap type dogs. Chows are extremely intelligent and unless you score 1200 or higher on your high school SAT's you should probably consider a Lab or a Golden Retriever. I believe the average Chow is smarter than the average dog owner. If your Chow does not like someone, neither should you. Chows hate cats.