Yeah they do look peaceful, but I think thats because they are fat and lazy, I'm told that they can be one of the most agressive cichlids of all though> someone correct me if i'm wrong though.
Yes sir you are wrong
. The thing about parrots is you could have the most sweetest fish in the world (my two parrots) if they take after the severum more, or if they take after the red devil your gonna have a killer. Parrots are great community fish, good in semi aggressive also. Even fish much smaller they will usually not be bothered, but if they are the last one introduced I would be more worried about the parrot, they are very very shy at first. I have several small peaceful community fish and a couple "aggressive" fish, they never fight with anyone and all the fish seem to respect their space when they need it. Parrots actually prefer to have "dither" fish, smaller little fish that can let them know what's going on, the parrots probably figure as long as the little tiny fish are swimming around without a worry then they have nothing to worry about, if they see a smaller fish get scared they will usually go hide to before they even know what they are hiding from. Try this, put in one parrot (observe him/her at the store, make sure it's a submissive one) and when he get's comfy (when he approaches you through the glass instead of zooming behind something) get him a parrot buddy if you can (smaller one might be better), they will "bump" each other but they will get over it.
The reason I say add a second parrot is well, when my parrot was alone he seemed sad, always sulking, I put a mirror up to the glass and he immediately swam over and started showing off to the mirror, he stayed looking at it for HOURS and would not move, he would swim slowly away from the mirror and he couldn't figure it out (cute). They seem to need the attention of other parrots. But as i've said this fish are very complex little guys, you could get one parrot and they might want to fight to death, just do it cautiously and if one doesn't work out try a different parrot, it is SOO worth it, these are amazing little fish, they will let you "pet" them, they will do random frontflips and backflips for fun, great little pets. Might want to keep your temp at least 80, they lose their color anything below that. Remember though, this is one of the most intelligent fish, they need a lot of attention.