Researchers at the Arizona State University and the University of Washington have debunked a common assumption that the field of biology no longer faces gender inequalities. They have found evidence of gender gaps in achievement as well as class participation in introductory college-level biology courses.

Sara Brownell, assistant professor with ASU's School of Life Sciences, said that until now it was believed that gender differences occur in fields dominated by males or where there is a strong emphasis on math.

Previous studies showed that more than 60 percent of those pursuing undergraduate biology majors and about 50 percent of biosciences graduate students were females.

"But we are seeing it in undergraduate biology classrooms that do not focus on math - where females make up about 60 percent of the class - indicating that this could potentially be a much more systemic problem. It's likely this is not unique to physics or biology, but rather true of most undergraduate classrooms," Brownell said in a statement.

For the study, the researchers analyzed 23 courses - mostly sophomores and biology majors - at a top research university for two years. Nearly 60 percent of more than 5,000 students enrolled in these courses were female.

The researchers found that despite similar college GPAs, female students scored 2.8 percent lower than the male students in college exams. Plus, 63 percent of males, on average, voluntarily responded to questions even though they comprised only 40 percent of the classroom.

"Introductory biology classes are the first opportunities for many students to interact with professionals and peers in their intended fields," said Co-author Sarah Eddy, a postdoctoral scholar at the University of Washington. "This is a critical opportunity to build up their confidence so that they can succeed in the field. Part of building that confidence is gaining recognition from their classmates and instructors. If females aren't heard as often as males, they don't have the same opportunity to succeed as biology majors."

In an attempt to improve student retention and achievement rates, the researchers recommend lecturers to randomly call students to answer questions rather than allowing students to raise their hands.

The findings are published in the journal Cell Biology Education - Life Sciences Education.