Some people believe that after spaying a cat that they will become more defensive or even aggressive. But this is simply not true, if anything spaying your cat will make their quality of life much better.
The belief that cats become more aggressive after spaying may be due to the fact that after they come home from the veterinary clinic, they may act out for a few hours upon returning home. The cause of this is unknown, but this behavior quickly disappears.
One of the main benefits of having your cat spayed is that they will not go into heat at all, so you do not have to worry about them meowing and looking out the windows and trying to escape through open doors whenever they are in season. Also male cats will stop coming around your house.
Also spayed cats are actually healthy. You do not have to worry about certain types of cancers, and on average they live slightly longer.
Another common concern that people have after staying their cats is that they will gain weight. Some people think that this might happen because of slower metabolism.
This is actually proved not to be true. Regardless of whether the cat is spayed or not most house cats are overweight and obese, simply because lack of exercise and too many treasures.
If you are still debating on whether or not to have your cat spayed please talk to your veterinarian. You'll see that the benefits far outweigh any possible risks that your cat might experience.