The school is heavily female in recent classes. The current first year class had 9 men and 54 women, with the majority being Asian. I don't think there has ever been any kind of "cultural divide" at UCBSO. Like any school, some students work harder than others. There are stars who are smart and work hard, there are middle of the pack students who are bright but lazy or not-as-bright but hard-working, and there are lazy not-so-bright students (who usually don't last very long). Some students are good academically, but not clinically. Some are good clinically, but less so academically. Some are good at both, and some are not as good as both. Some classes are more laid-back, while other classes study more overall. Every class has its own "personality", and that's something that you can't predict. The vast majority of students are interested in helping their classmates to succeed, though there will always be a few that want to step on you as they climb to the top. More students are "humble" rather than "arrogant" or "boastful". Remember that if you were accepted, it means that you did something in your academic career to convince Berkeley that you can handle the program, so you shouldn't feel that you somehow are not up to the task.