Are they really so, or is it that *we* as humans
have imprinted that notion into their DNA with our thinking?
You can't do that. This is one
of the weirdests thing I've ever read. How exactly do you think
that thinking manages to alter germline and somatic DNA? The
whole idea strikes of 1st millenium magical thinking.
I've noticed on more than one
occassion where someone with their dog
was walking along with me and mine, and they would see a certain breed
of dog, like a pit bull, and say something like "get your dog on a
lead, that pit bull might attack!" and I would see the pit bull tense
up and tail in the air, ready for a fight .. where it was quite
peaceful before.
You are staring rigidly at the dog,
which is an aggressive signal, the dog responds accordingly.
Maybe you tighten the lead drivng the front end upwards with is a
secondary indication of aggression and dominance. The tighness on
the lead also creates stress for your dog which in turn changes it's
normal behavior.