Although female students in the physical and life sciences performed slightly better academically than male students, the males were perceived as more competent, a new study from Colorado State University researchers discovered.

“We found that 1) in both life science and physical science courses, women had statistically higher course grades than men, higher university-wide GPAs than men, and were 1.5 times more likely to earn an A or A+ than men,” concluded the study, published in the open access journal PLOS. “[A]nd yet 2) both men and women identified women as students they study with, seek help from, find knowledgeable, and perceive as the best in the class at lower proportions than the actual success rates of women in their classes.”

Researchers evaluated 2,866 student grades in university science, technology, engineering and math classes that allowed for group work or laboratory work, which enabled students to get to know their classmates. Then, 935 students filled out a survey answering questions about whom they studied with, which students they approached for help, and who were the “best students.”

“The assumption has been that if you have the numbers, if you just increase the number of women, you won’t have bias,” co-author Meena Balgopal, a professor of science education at CSU, told the university’s news publication. “But we find that’s not the case.”

The authors warned that stereotypes about women in technical fields can linger, and people may reconcile the achievement gap by concluding that men are innately knowledgeable but lazy, or that women have a natural deficit but work to overcome it.

“The endorsement of gender bias can lead aspiring women to decrease their interest in STEM, their self-efficacy, and their performance both individually and in teams, and ultimately lead these women to pursue other disciplines,” the report noted. Researchers from CSU and California State University contributed to the findings.