Which of the expressions suggests that people are inclined to be aggressive and violent towards one another?

A wolf pack is far more civilized than a pack of humans. They each know their duties, and work together. As for humans, of all colours, well we can all see how foul they can be. Greed and jealously play to big a role in humanity.

the sad thing is that the Indians were labeled savages despite the fact that the white man came over and started the war with the natives and they get labeled as gentlemen in my opinion the labels should be switched the non whites should be labeled gentlemen and the whites should be labeled as savages

Addam, the native Americans you speak of were savages. the thing is that they were always fighting other tribes and the brutality was not only towards what they considered their enemies. I agree that we took the whole of the United States from all the tribes. we unleashed terrible trials and tribulations on them. some sided with us to bring in a new age and a new country with an experiment in democracy. the past is not what we are today. facts are facts. the governing politicians set things in motion for the rest of us then and now. I, for one, am proud to be rid of the British,French, and Spanish monarchies. I am proud to be an American who would still fight against Tyranny

Was it intentional that Freud's quote starts with Men and not Man, as there's an obvious difference?

I agree with Freud, man loathes others at times and wants to take and steal by whatever means, Wolves are beautiful animals that live and die for each other, they hunt together and raise cubs together without them we wouldn’t have the dog for a companion which in my opinion is often man’s best friend.

addam , what a chappy, one-sided approach!!! Indians, generally, we're dedicated, sophisticated warriors.