Any truth in racial stereotypes? Can you give any examples?

Irish are stupid? Scots are mean? English are effete? Americans are brash?. I don't really think so but when some one IS - is it extreme? Example: On an army exercise with a Medical unit on Salisbury Plain.February 1970 A group of bandsmen were standing about waiting to be 'processed' as casualties. They tried to make a fire but all the foliage was wet. Along comes Driver 'Paddy' and pours some petrol from a 5 gallon jerrycan which promptly catches fire. Paddy holds the blazing 'can to his face and tries to blow out the fire. - A very unsuccessful act. The rest of us shout 'Get rid of it' or similar. Paddy the throws to the the doorway of the evacuation tent which is full of squaddies strapped to stretchers. Panic! It is eventually extinguished by another 'Paddy' who calmly applies a fire extinguisher. Has any one else any similar stories? Does it apply to all sterotypes?