Difference when it comes to ethnisity?

hi i know a boy who claims he was born in Colombia. i believe him, but he has no colombian or south american roots, i know because he told me. my mom was born in Colombia and has south american and colombian roots. i say he was just born in colombia, not a true colombian, like my mom. whats you're take on this? we have been bickering over this for a while, and quite frankly, we want an answer!! ha ha! please help. :) (if you are a colombian or south american that might help as well!) thanks again. :)