The phrase “to stick one’s neck out” means: To expose oneself to criticism; to take a chance, especially an extremely risky one; to monkey with the buzz saw.
Although this American slang is of considerably later vintage, probably little more than thirty years old, it is our opinion that it arose also from the nineteenth-century slang, “to get it in the neck,” or “to get it where the chicken got the ax.”
That is, as anyone who has beheaded chickens has learned, when the creature’s head is placed upon the block the animal will usually stretch out its neck, thus making the butcher’s aim more certain.
Just some physiological reaction, we suppose.
Of course, the expression could have originated from the victim of a lynching bee, but we do not think so.