Talk:Mac Scorpio (John J. York)/@comment-98.236.2.100-20130716133453/@comment-3418856-20131018093003

Because John York is American and Tristan Rogers is Australian. When Mac first came on the show, he had an Australian accent, but it wasn't very good. Because of that, and because he's actually American, it went away over time. But, in actuality, just because two people have different accents, that doesn't mean they can't be full siblings, or even have been raised together. For example, if the family moves when the younger child is little, they can end up with a different accent. People can also teach themselves to speak with a different accent well enough that it comes naturally to them (such as Scottish-American actor John Barrowman from Torchwood/Doctor Who). He actually had a Scottish accent, but he moved to the US when he was like 8 and trained himself to speak with an American accent to fit in.