I remember reading a term for the phenomenon of being more aware of the differences between groups when you're a member of such a group.
Here's an example to illustrate it - if you grew up in the Soviet Bloc (or perhaps even in one of the countries today), you'd know all of the stereotypical differences between a Serb and a Croat, between a Czech and a Russian. But if you're from another area entirely, to you they're all Russians.
Similarly, if you're from a Latino country, you'd know all of the differences between a Cuban and a Puerto Rican, between a Dominican and a Mexican. But if you're from another area entirely, to you they'd all be Latinos, as one homogeneous group.
I'm not just talking about the phrase "detail-oriented" - there was a specific term for this quirk of humanity. Anyone know it?