I've heard that piebalds are notorious for having a particular "temperament", but what does that mean? That they are picky eaters? That they are nippy?

(I have two piebald females and one het male, and they are all outstanding eaters. The het is a bit nippy, but the pied girls are very sweet and gracious about handling. What IS striking about my two pieds is that they are LAZY. Good grief! My black pastels eat the same as the pieds, but they are all over the place when I take them out, exploring and climbing and flicking, while the pieds just curl up in the first warm place they find and go to sleep. Sometimes they can't be bothered to leave my lap! They're like CATS. They're so lazy, even my non-snakey friends have commented on it.)