Actually, since an organism's greatest enemy is usually its own species (since it has the most in common with it and therefore is fighting over similar resources) it makes a little sense for humans to find other humans more distasteful than, say, some other species. --Especially when those species are cute and fluffy and share our lives and, generally speaking, can give us less noxious experiences than run-ins with other humans.
I was always an animal person. Preferred them hands down. I always found it strange though that I didn't go into Zoology or something related and instead am studying the human brain... hmm...
My empathy for other humans has increased since I've been with bf. Don't know, maybe he's just revved up my oxytocin/vasoppressin more so that I find babies a little cuter and people a little less annoying. --One thing I know is that I'm the one that's changed because surely babies are just as ugly as they've always been and people are just as obnoxious.
Still adore animals though.