> "most Americans of their intelligence would be aware"
that would still leave up to 49% Americans not being aware. so how did you conclude that they were not Americans? Also, how did you measure their intelligence?
> "slightly more common among immigrant families than locals"
even if true, how did you conclude that these were not Americans?
> "Americans, on average, are more individualist and hesitate more when asked by family to do something criminal"
even if on average Americans are more so, how did you conclude that these were not Americans?
> "A lot of immigrants eventually adopt anglicised names"
from your sentence it seems a lot of them don't. so how did you conclude that these were not Americans?
It would be a disaster for immigrants in your area if you were ever hired into some kind of investigative/law enforcement role.
I take it you're not in HR at the CIA or FBI, which vet applicants' families for a reason. i.e. how long ago applicants and/or their families came to the US does help predict their loyalties... It might not be a strong nor fair predictor, but it's not zero either.