I did once buy turkeys off someone who thought inbreeding didn't matter with birds etc, only mammals, and they bred turkeys who would always attack once your back was turned. They'd kept their toms in with a pig and the pig lived in fear of them.
Since these were my first ever turkeys, they were predestined to be food anyway, so I didn't mind. Otherwise I never would have bought off them. As you'd expect, from such unsocialized parents came antisocial chicks that bullied chickens enthusiastically, and once toms reached adulthood we had a few start displaying at us and hurrying towards us when our backs were turned.
If they display at you and gobble when you speak, you can probably safely assume you're on their target list. Not that these signs may be present even if you are. And a family member was responsible for getting them to view all human talk as challenging them, because they'd repeat the gobbling noise every time the turkey did it and as with chickens this led to the animal making the noise nonstop and every time humans talked within earshot. I am a firm believer that for the animal to respect us, it does not need to view us as a bigger male or female of its own species... I believe that to be faulty logic. It requires backing up physically to prove such dominance and that leaves children etc at a potentially fatal disadvantage. My animals will respect humans because we're humans, not because we are all able to assert dominance. If they ever show disrespect I cull. It takes an aberrant mind to show that disrespect in the first place.
Anyway, the next batch of turkeys we got were fine with people but gradually I wound up with no toms because the males kept killing new hatchlings while trying to mate with them. They went from being exemplary fathers to killing without warning. Every time it happened I'd cull the male and breed a different one. Some of the males would also suffer a snap of sorts where they would try to kill a female while trying to mate with her. Culled those too. With all of these aberrant behaviors there was no warning whatsoever. They were fine until their second breeding season and then they just began acting psycho.
One of the females from this family took such exception to my continued interruptions in her breeding plan that she started seriously attacking me too. Stupid thing would never brood anywhere safe, she preferred the side of a public road to a cage or our own paddocks. We had large uninhabited paddocks as well as the ones used by the chooks, it was merely a case of her preferring the road.
From my experience with turkeys, these varying negative traits (as with chickens) are heritable, but seem more weakly heritable than chickens's behavioral issues. They take longer to surface too. Each family line I had carried distinct behavioral issues, with the males and females having their own variants on it; aggression to other poultry was a big problem for some. A permanently hysterical sort of mindset was another issue with some others. None of my males ever lasted for more than two breeding seasons due to some severe and sudden behavioral fault rearing its head without warning. This I think has a lot to do with most breeders I know only breeding their under-year-old males and culling them before maturity. The mindset they will display at maturity remains unknown until you let them reach maturity like I did. But it's being passed on stealthily nonethless.
They can be very dangerous. I would source my next family lines of turkeys carefully in future. Since these were all just interim measures designed to get us home grown turkey flesh ASAP, this was not really an issue for us, though one aggressive female did destroy a whole clutch of chicks by scratching the ground in warning to us whenever we approached. (She crippled them and they died). So sometimes the turkeys themselves cost us clutches.
Good turkeys are no trouble. Bad turkeys are a huge amount of trouble.
The only truly sweet turkey I had was not worth breeding, because she had that inherited disorder that caused her to spasm whenever she heard water drops, so she always risked drowning in the rain. In short, there were endless bad breeders of turkeys in my area and in future I will be more picky, but they served their purpose at the time.
I don't think I have ever had it articulated that clearly before, but I do believe it.
