I like to have two cats, one male and the other female. In my experience, this is a good thing because they can keep each other company without fighting over territory. They kind of balance each other out like people do. I think two male cats could be trouble (fighting) and two female cats, I’m not sure. There is also more to behavior than gender. I’m guessing it is a complex thing (involving their experiences when they were young, genetics, and other things perhaps), not unlike human behavior. Cats have temperaments like people. My male cat is the calmest, most laid-back cat I’ve ever had, while the female is very high-strung. You can tell a certain amount about a cat from its breed, but if you’re adopting a cat they are often not of a single breed.