To answer that question, I think all one has to do is look at history. The ancestor of all breeds of chickens we have today is the Red Jungle Fowl. That domestication happened between five and ten thousand years ago.So I constantly see people breed for color traits. Does anyone breed for personality traits such as protectiveness or friendliness or handability?? Is there any research as far as passing personality traits? Thank you.
All breeds have extremely unique characteristics, including temperament and personality.
They acquired those traits over time and they became known to be characteristics of the specific breeds. They don't all have the temperament of Jungle Fowl due to selective breeding. But it didn't happen overnight.
In one or two generations, one isn't going to change temperament but over time it happens. People work for decades to achieve the characteristics they are looking for. So one shouldn't expect repeatable, noticeable results in one or two generations.
I never breed a human aggressive because I believe the chances are his descendants will have a better chance of being human aggressive.
I've never been attacked by the breed I currently raise but their temperament is much like that of jungle fowl. They are aloof and just have no desire to have human contact.