Chivalry. It's not really behavior so much as "I'm more powerful than you and I want your daughter, give me your daughter or I'll kill you", but your history teacher will want the answer chivalry, so I suggest you answer that, lol.
Answer:
Solutrean Hypothesis, Hope this helps :]
For most of its early history, the United States played a small role in world affairs. But in the late 1800s, some of America's leaders called for the nation to join the ranks of the world's major powers. As a result, the United States began to acquire influence and territories outside its continental borders. The country was abandoning isolationism and emerging as a new power on the global stage.
Hector is the answer.
hope it helps!