same principles apply...in science as well as life...

like nanoparticles that tend to coagulate together in order to minimise their surface energies, people tend to group together too, especially if you are from the same countries...

examples:

i) a russian classmate of mine stays with her fellow russians in the same apartment
ii) a brazilian classmate does the same thing too...
iii) so are all the ethopians, nigerians....

so where does that leave me??