I started a new game of Civ4 (with BTS and Extra, if that helps), and the AI seemed ridiculously aggressive. They were mostly passive-aggressive, but they had their war as well. They were making ridiculous offers that I couldn't accept (such as a tech for a tech, in which the one they wanted required at least 3x science), and they would get mad after I kept rejecting their offers. On top of that, demands for tribute were very common. I was demanded tribute by a civ the turn after I discovered them. I finally raged quit when 2 civs declared war on me, captured a city of mine, and had over 20 ships on one tile of my coast... all in one turn. The thing is, I did nothing to them. I didn't blockade routes, declare war, demand tribute, attack under cover, or even take over a city with culture. What can I do to lower their aggression? And no, none of them were Ghandi.