As someone who lives with 4 cats, one of which who is orange and conforming with all stereotypes, I implore you to further that line of inquiry. While the OP paper doesn’t claim behavioral differences are supported, it doesn’t falsify them and there could be a dynamic there. If you could genetically encode shamelessness it might encapsulate the behavior. It’s not a lack of intelligence per se, more of a lack of inhibition.

This paper demonstrates a connection with behavior. I personally suspect gingers have smaller amygdala.

https://www.researchgate.net/publication/381166835_The_Skin-...