I found a good definition of Yankee right here
Yankee: northerners that have very thick accents and are often quite stuck-up. They typically think that they are walking geniuses and act like they know EVERYTHING which can be quite irritating. Yankees often think they have the right to travel to southern states and try to correct southern 'rednecks' on how to speak or what 'proper' grammar is. Yankees are often very judgemental of the southern 'rednecks' and put many of them down because they have accents or dont use proper grammar when really it's just the way that the southerners were raised, and assume that all southerners are 'uneducated, incestuous, and racist'. Yankees also have problems admitting when they are wrong and saying sorry, instead they choose to be smartasses about things.
(not all northerners/yankees are like this, but the vast majority of them are)
you also forgot that when they start to get annoyed, angry, or upset, they start talking 50 times faster than normal.