
bookrat |

I house rule it like this:
If it's a cultural thing that can be learned, you can get it through adoption. If it requires actually being that race, then you cannot.
Example:
Adoption can give a human a dwarven hatred (a dwarf racial trait which is taught by special training), but it cannot give Elven Reflexes (a half-elf race trait, which requires elven ancestry).
This ignores the "racial vs race trait" confusion, and in place puts a more realistic option for adoption.
However, if you're going PFS (and if adoption is a legal trait in PFS), then it is vital to learn the difference between racial and race traits, because you cannot get a racial trait from adoption, but you can get any race trait from it.