College students who thought their high school classmates were interested in science classes were more likely to intend to pursue STEM careers, a new study reports. The results of a cross-country survey suggest that motivating high school classroom environments may be "contagious" in positively influencing students' STEM interests. Given the national push to increase the STEM talent pool in recent years - as a result of students opting out in favor of other preferences and under-representation in related professional fields - it is critical to understand the key features of educational environments that facilitate recruitment and retention. To better identify those attributes, Zahra Hazari and colleagues collected data from students in mandatory introductory English courses at 50 randomly-selected colleges and universities across the United States. They asked participants to report their likelihood of pursuing a STEM career, as well as how interested their peers were in their last high school biology, chemistry, and physics courses. The researchers also accounted for influences such as teaching quality, academic achievement, and family support for science and math. The survey showed that only 40% of students in high school classrooms with perceived low levels of interest showed STEM career intentions in college, compared to 65% of students in classrooms with perceived high levels of interest. What's more, peer interest was linked to either improved or maintained grades in high school biology, chemistry and physics. The authors say that future research should further investigate the mechanisms by which interest is transmitted among peers, and how students engage in active learning.