Reputation is not Attitude.
Rep is your 20t deals capability.If you don't break a 20t treaty by your side,or you kill the betrayed civ before he/she contact others,your rep is good.
Breaking rep can be:You declared war with trading civ,when you have something to give in a 20t deal;Warring civ cut the trade route,when you have something to give in 20t deal.Your trading resource is cut down from your empire.You sign a peace treaty with common foe of MPP/MA.You sneak in other's territory and declared when being booted(Compuslry Out or not,it counts the same).Someone said there're three indivisual reputations:Trade,MA/MPP/Embargo,ROP.Peace deal violention is not punished.
Attitude is a civ's mood at you,they are:Gracious,Polite,Cautious,Annoyed,Furious.The more "good" the attitude is,the less chance they'd declared war on you.
Mood is by those factors:Civ's Aggression level,the Culture Circle of the contacting civ(Same Circle reduce 1 annoyness point),the trade,the demand,the embassy,the war,the raze,the pillaging,the disbanding slaves,fighting common foe,the MPP/MA/Embargo/ROP.See articles in War Academy.