This is a difficult question. Science students can sometimes be smarter than art students. But art students can sometimes be smarter than science students. It also depends on what you mean by smarter. In order to compare science and art students, you need a test that measures innate abilities rather than learned abilities. Otherwise, it is not a fair test. Some IQ tests do this fairly well because they try to ignore culture. Such as Raven’s Progressive Matrices. But there are other factors in how to estimate your IQ. Academic achievement is just one of them.
It may very well be that one art student is smarter than most science students. For instance, Richard Feynman was also an artist and musician, not just a theoretical physics professor. And just to be sure – being smarter is not a replacement for a solid work ethic or other personality qualities that also help people excel in life. But here are some results of estimated IQs for different academic majors (1). The higher the better, and 100 is average.