User blog comment:D1M3N510N5/Top 10 Most Popular Total Drama Contestant (viewer's vote)/@comment-12762816-20140514062350/@comment-24152851-20140514062657

True, but I think the writers have intentionally put in an ambiguity joke about their individuality. In the Playa de Loser episode (I think) Chris says: "Katie and Sadie still share a brain."