I don't think you can really generalize. Horses all have different personalities and I don't think bloodlines have alot to do with it.
I agree there to an extent, While I don't think you can deem all Hancock horses as had to break and all Zippo horses as something else... A lot of personality IS passed down threw parents who got it from there parents and so fourth.
My appendix colt for example, His dam is Calvin Sacket/Dodgers Playboy bred Foundation QH and he carries about 25% of her personality traits, expressions etc. While his sire is a Raise A Native son, Thoroughbred. From what I've read on and known of his sire he was athletic but lazy and also 98% of the pictures of his sire are of him rearing, bucking, hopping, leaping and bounding in one way or another... 75% of my colts personality is more athletic than any horse I've known but just you try to get him to move! Lazy! Slow. BUT boy does he like to show off bucking, rearing, hopping, leaping and bounding like his sire... when its his idea of course.
That said I can't say all of this stallions foals are like this, but I knew many who are. And I'm sure this is passed on from his foals to there foals and so on.
Back to the question I have owned four (training project/resce) Zippo bred horses and known friends with two - All have been stubborn and to put it bluntly quite dumb. It might just be the luck of the draw on who I've had/known but might be a streak in the line.
Last edited by New_image; 10-13-2009 at 12:21 PM.