Welsh Baccalaureate help

Hey all!

So I have been told to make a start on my individual investigation over the summer holidays but I have no clue what to do it on. I was told that it might be better to do something which relates to what I wanna study at University, which for me is either Psychology or Social Science. Because I'm applying for both of these courses, my mother thinks that I could do something where I could bring both the psychology and social science aspects into it. I think this is a good idea, however, I'm not too sure on what I could do that both could be brought into it. Any ideas?