There is a certain developmental psychology prof in Penn whose research works I have been following and would love to work with but he only mentors grad students. How easy is it to take graduate classes? I’d love to take his classes!
My brother took some grad classes in math as an undergrad at Penn. My guess is that it will be up to the professor.
Varies by prof and department. Try emailing Claire Ingulli at cingulli@psych.upenn.edu who oversees psych dept advising for undergrads and can probably tell you if it’s a possibility.
Also, you wrote the prof only mentors grad students, but is that the case or is it that he only teaches grad students? Plenty of students conduct research with professors who only teach grad students (e.g. All the students who do research with med school profs). You don’t necessarily need to enroll in the professor’s class to be mentored or do research with him.
Definitely duable and there are people every year who submatriculate. I know someone submatriculating in Physics for example. Undergrads can definitely take classes in the grad schools. You obviously need credentials though but yeah, definitely possible.
Quite easy to take grad classes as an uperclassman in my experience. You just have to get permission from the department/instructor in some cases, in other cases not even that.