Not sure what it is about Cinnamons, but every one I've been around for any length of time seem to have a little bit of a 'Tude.
The breeder i got my cinny from said darker morphs tend to be more aggressive. I had posted a topic about it Awhile back and most people agreed. Jen, from LLL Reptile, who im pretty sure has raised thousands of bps, was one of the people who said she noticed this trend too. (im like 99% sure it was her but dont quote me on that)...