To remedy the disparity between sexes in science, technology, engineering, and mathematics (STEM) fields, it is important to understand the factors critical to initiating and maintaining STEM interest. To this end, we created and administered a survey to almost 8,000 individuals in and outside of STEM fields. Our results shed light on the various factors that are critical for sparking STEM interest and persisting in STEM fields for each sex as well as the differences in movement in and out of STEM pathways for each. These results reveal that although there is no singular pathway into STEM fields, self-driven interest is a large factor in persistence, especially for males, and females rely more heavily on support from others.