Reading an article on primate culture and violence this morning I was struck by the following sentences...

Some brain–imaging studies have appeared to support this view [that humans are hard-wired for xenophobia] in a particularly discouraging way. There is a structure deep inside the brain called the amygdala, which plays a key role in fear and aggression, and experiments have shown that when subjects are presented with a face of someone from a different race, the amygdala gets metabolically active—aroused, alert, ready for action.

...

More recent studies, however, should mitigate this pessimism. Test a
person who has a lot of experience with people of different races, and
the amygdala does not activate. Or, as in a wonderful experiment by
Susan Fiske, of Princeton University, subtly bias the subject
beforehand to think of people as individuals rather than as members of
a group, and the amygdala does not budge. Humans may be hard–wired to
get edgy around the Other, but our views on who falls into that
category are decidedly malleable.

Which I thought was pretty interesting. Nice to see good science backing up good philosophy. Actually the whole article is a good and interesting read.