So you're saying it's human nature to have morals?
If you believe that humans are animals (with a higher level of intelligence), our base instinct is for the preservation of our species, and a part of that is protecting the "herd". Therefore, there are societal norms that we will enforce on the whole so we can survive.
Best explanation I've heard. Thanks, Panj.
Thanks. I don't like talking about "morals". I look at things as "norms".
Most animals stamp out dischord in their herds because it upsets the herd. Lying, stealing, infidelity, greed, etc. are all things that cause discord between members of the herd, therefore, we look down on them, and in some cases punish them, because we are trying to bring harmony back to the group.
You can see a lot of this in mammals. The more "evolved" the species is, the more social norms you see them enforce. Primates, specifically, exhibit a lot of "human" traits in their social interactions. The thought is that the more intelligent we become, the more intricate our social interactions, and the more advanced our concepts of right/wrong, moral/immoral, etc. are.