Male cichlids with developed nuchal humps are those that have established their dominance over an area.
The same is true with flowerhorn cichlids. Only when a male flowerhorn has completely established dominance over a territory will the development of kok starts. This is the main reason why you should never put a small fish alongside a larger one.
While louhans are generally aggressive, there are those that are scared of anything that moves. Here are the things you can do to help this kind of fish: