i think if you were born in america you should just say youre american..nothing else
UNLESS
you're a first generation american and your parents raised you in a home where you grew up speaking italian, spanish, german, farsi, etc., and on a regular basis ate italian, mexican, peruvian, german, middle eastern etc. dinners, and you grew up being bred by your family to root for the italy, mexico, germany etc. soccer team, and know at least 10 italian, mexican, german, afghani etc. classic songs. to me this says within your home (which is where your foundation comes from) you were basically raised by a pretty authentic foreign culture and thus would make sense for you to say i am mexican american, italian american, german american, etc. if you dont even speak the language of the second culture you try to claim....i say bullshit.....go to that country and see how well you fit in....you won't..so why claim it?
i had some girls from ireland stayiing at my house and they thought it was funny how every white person here would be like "I"M IRISH!!!" they may speak the same language but these girls agreed...95% of americans claiming to be irish-american have nothing irish about them