While breeds do have tendencies, each chicken is an individual. You have to have enough for averages to mean much and you don’t. The one that becomes queen is the one that wants it the most. That’s not based on size, that’s based on spirit. In some flocks with both bantams and full sized chickens a bantam rules the roost.
Chickens mature at different rates. As Azygous said you can easily see changes at any time, but when they are going through puberty and becoming adults is when you may see the most changes. A lot of times these changes are so peaceful you don’t even notice it. Occasionally you may see some fighting but even then it’s usually not that bad. You read about some horror stories on here and they can possibly happen, but usually it really isn’t that bad.
Some hens rule the roost with an iron fist, while other head hens are much more laid back. You may or may not have troubles even knowing which is in charge. They are living animals and each has its own personality.