Can pets read human emotions?

I can say without any doubt that our cat definitely reads what's going on with all of us. Not just emotions either... she can tell when one of us isn't feeling well and she'll come lie down by the bed or sofa or sometimes climbs right up there with us. :-) I think she's more tuned into my daughter than the rest of us but that may be my imagination. And then there's this "look" she gives me when she knows I'm upset or sad about something... it's like she knows exactly what's going on. Sometimes it's comforting and sometimes it's more unnerving!