What early experiences attract students to pursue an education and career in science, technology, engineering, and mathematics (STEM)? Does hands-on research influence them to persevere and complete a major course of academic study in STEM? We evaluated survey responses from 149 high school and undergraduate students who gained hands-on research experience in the 2007-2013 Aspiring Scientists Summer Internship Programs (ASSIP) at George Mason University. Participants demonstrated their strong interest in STEM by volunteering to participate in ASSIP and completing 300 h of summer research. The survey queried extracurricular experiences, classroom factors, and hands-on projects that first cultivated students' interest in the STEM fields, and separately evaluated experiences that sustained their interest in pursuing a STEM degree. The majority of students (65.5%, p < 0.0001) reported extracurricular encounters, such as the influence of a relative or family member and childhood experiences, as the most significant factors that initially ignited their interest in STEM, while hands-on lab work was stated as sustaining their interest in STEM (92.6%). Based on these findings collected from a cohort of students who demonstrated a strong talent and interest in STEM, community-based programs that create awareness about STEM for both children and their family members may be key components for igniting long-term academic interest in STEM.