If you want to do research, you’re likely look at grad school and research experience as an undergraduate will be very important. Either major will be fine. Take a look at the courses to see which interest you more and major in that. You can always augment your students with other classes of interest outside of your major. Make sure you get involved in research as an undergraduate to make sure that you actually want to pursue research/graduate school and to get a better idea of the kind of work you want to do.