[Daynarr]

I'm not sure but I believe that ‘Regular Decrease’ value located in AI Anger file affects it. AFAIK each empire has one anger value for each empire encountered. So all these parameters located in AI Anger and Politics files work together when determining attitude towards MEE empire.

It is very possible, on the other hand, that base anger level for MEE determines the lowest possible anger value while that empire is MEE. I just don't know.