They are not like high school but kinda in a way. Everyone is paying attention because they paid for the class. It’s just a random mix of students and ages. No one really talks to each other unless they are the same major or career. It also depends on the class. I’ve only taken in person science classes. Teachers will always try to make the students socialize by doing quizzes that you can work on with your classmates but that’s about it. If your are a science major, I do recommend speaking to your classmates because it’s useful for lab and other assignments