I find evolutionary-psychological reasoning always a bit suspect because it seems a bit too good to explain just about anything. Having said that -- sometimes dogs seem to have a sense of guilt -- does that imply they have a kind of morality too(*)? Or is it just some kind of 'act' due to co-evolution with humans?

(*) De Waal in Primates and Philosophers argues that some animals have a certain degree of morality (Robert Wright slightly disagrees with De Waal, in the same book).