I didn't (I only really know old Who from memories of watching it behind the sofa in the seventies) but I looked it up. I think they're definitely going for a what makes us human/what makes them machines angle but I get the sense that the answer may lie as much in nurture as in nature. It's, I think, significant how little attention Sarah pays to how she treats Cameron. She manages her but doesn't seem interested in teaching her. But it's unclear whether Cameron is interested/programmed to learn or simply to observe/record.