What is the difference between a BA and a BS in Psych? Besides the classes I mean. I know BS is more for biological things and research, but what if I want to do research on how environment effects personality or disorders? Do I get a BA in psych then go to a specific field for my MA/Ph.D? Or do I have to still get the BS?

I am currently in the BS Psych program but I am not interested in nor do I perform well in any of the interdisciplinary classes for it. They are bringing my gpa down and I have had to withdraw from one already. Would it be better to switch to the BA program?