Greeks are from the Mediterranean, Russians are farther north, their languages are different, etc., etc. To me, all these things caused them to develop differently, and so they are different cultures.
The Dutch and the English, however, are inhabitants of lands in the same general vicinity, share a common religion (Protestantism, if I'm not mistaken), and their languages (again, if I'm not mistaken) may be related. If this is true, then I would think they are more alike than different. I readily grant that I might be wrong on this, but as I said, I don't know, and was hoping you'd tell me more than "yeah, they're different".