Just a rumor that I've heard a lot. I, myself, do not raise turkeys, so I cannot personally be certain either way of whether or not they are particularly "dumb."
Tasty, too....That makes sense!! Turkeys seem awesome.like giant feathered dogs
and others that were very very smart.
oh trust me, I eat turkey too!! But not sure I could ever eat one after owning one haha although I love my chickens a lot and still eat chicken so never say never I guess, right!? 
Chickens can be taught also.
And I think the intelligence thing depends on the chicken because I’ve had some chickens that, although very lovable and sweet, were dumber than a bag of rocks
I’ve had chickens get “stuck” in the run frequently and pace the fence line even though they’re 5 years old or they’ll get separated from the others cause they’re so food obsessed they don’t notice they’re missing. Or they’ll go stand right in the middle of the wide open lawn despite experiencing hawk attacks.
Meanwhile I’ve had others that learned their names, learned to follow anyone with a shovel, jump up to greet me and demand to be let out, figure out how to sneak past me to get out, etc.
I’ve even heard of chickens learning to play the piano!
right!? The worst (or funniest!?) is when they see their friend just outside the fence so they try to go that way and freak out and don’t seem to grasp to just go out the door and go around. I’ve had them come even within like a few feet or less of the door, almost all the way out and then turn around pace again they usually eventually figure it out but not always and I’m like OMG!
Soooo pretty
