This is a difficult question. What many people don't understand is that each bird species is different in behavior and personal traits. Then to top that off, each bird has their own individual personality. To help you understand, I will use the following example. Conures- that is a species of bird. But within the Conure family you have many types of Conures. Then you have subspecies. Conures in general are not all going to be the same. Different behavior, habits, vocalness etc. Then each bird has its own individual personality. The same would apply with the Parakeet family. Just to name a few, American Budgie, Ringneck, Quaker, Rosella, Scarlet Chested, Mustache, and Lineolated. Then environmental factors play a part of how the bird is going to be. Can that individual bird tolerate dogs barking, kids yelling, loud music, quietness, etc. Each bird would handle their environment completely different as a human would. Whether you purchase a baby or a older bird, once you remove it from its original environment and place it in a new one, there is no way to predict how the bird will respond. The bird you meet here, may or may not change in its now home with you. Just as a child on its first day at school. Some will be scared, shy, quite, observe, or fit right in. Then later as the bird matures, hormones start kicking in naturally. Birds moods can change during breeding season and molting. So in other words, its hard to predict what bird will work for you based on personality once its rehomed from its original home. You can however decide what type of species would work for your environment and lifestyle.