IME, jags probably have the most variable range of temperments of almost any c.a. cichlid. The only general trend is that most jags aren't complete pushovers, they don't really take much crap from other fish, but alot aren't outwardly aggressive unless provoked. I've had some very peaceful jags who lived fine with firemouths, jds, etc, and other jags who were mean to the point of beating up a same sized male dovii and citrinellus, killing my male motaguesis, killing various pike cichlids, target/dither fish, etc.