Interesting. My logic behind thinking that there is a genetic component to aggression is due to the wide personality differences I have seen between different breeds. Certain breeds/lines of breeds in my experience can throw an abnormally high or low percentage of aggressive offspring, comprising a trend rather than a one-to-one correspondence between sire and offspring temperament. What do you think about that?There would seem to be a bit of a verification problem here. Given that those in this thread who believe, or even suspect that human aggression in male chickens is an inherited trait and given that many who believe this kill a rooster apprently kill any rooster that shows signs of human aggression, the chances for the "it is inherited" camp of proving their point seems pretty remote given in that dead roosters can't produce offspring to test the theory out.
On the other hand, on this thread, DobieLover and I have both had human aggressive roosters who, with some patience, work and an understanding of what may trigger such aggression, have not only reduced their aggressive behaviour to a manageable level but have also produced some real sweethearts as offspring.
FWIW, I keep and breed some aggressive cocks because I don't think the genetic influence is that immediate.