Here is the article's abstract:
Concern has been raised that segregation of girls and boys into separate classes leads to increased gender stereotyping. We tested this in a sample of 365 seventh-grade students attending a junior high school that offers both gender-segregated (GS) and co-educational classes. It was found that for both boys and girls, the more GS classes they took in the fall, the more gender stereotyped they were in their responding in the spring (controlling for initial levels of gender stereotyping). We concluded that GS likely heightens the salience of gender in the classroom thereby reinforcing and increasing gender stereotypes. As such, we argue that GS is a misguided approach to addressing any educational difficulties girls and boys might be having.
Citation: Richard A. Fabes et al., Gender-Segregated Schooling and Gender Stereotypes, Educational Studies (2013).