As background, I just purchased a VOS (I believe) Eclectus from the owner of a local pet store. His name was Butch which I detested because he butchered his feathers so badly. I named him Solomon and call him Sully. Since being in my quieter less active household Sully has not plucked once. In the pet store he was faced with about 15 or more birds (3 of which were Cockatoos) and it was noisy. Many people came in and out; it was, to be kind, hectic there. Sully is a quiet, calm, lumbering giant. I believe I am Sully's fifth owner, the original who lost him over 8 years ago, the owner of the pet store, and two separate households who both returned him to the pet store for screeching and biting. Sully is a quiet soul and he has stopped plucking, has never bitten me except once in the pet store, which I believe was my fault, and Sully has completely stopped screeching. So I believe nervousness caused by a hectic atmosphere can be a great factor in plucking.
Now my problem is that Ana Grey has learned from Sully to screech, much too my dismay!!!