A friend sent me an NBER working paper on academic performance by classroom structure. From the abstract:
We estimate the causal impact of school and classroom gender composition on achievement. We take advantage of the random assignment of Korean middle school students to single-sex schools, co-educational (coed) schools with single-sex classes, and coed schools with mixed-gender classes. Male students attending single-sex classes within coed schools score 0.10 of a standard deviation below male students in mixed-gender classes, and this achievement gap is entirely accounted for by classroom gender composition. Conversely, male students attending single-sex schools outperform their counterparts in mixed-gender classes by 0.15 of a standard deviation. The significant impact of single-sex schools on male students' achievement are not driven by classroom gender composition, but largely accounted for by increases in student effort and study-time. We find little evidence that classroom or school gender composition affect the outcomes of female students.
Source: All or Nothing? The Impact of School and Classroom Gender Composition on Effort and Academic Achievement by Soohyung Lee, Lesley J. Turner, Seokjin Woo, and Kyunghee Kim.
Now a paper that uses representative U.S. data came out in the American Economic Journal, and it confirms that distraction is real:
This paper finds that a student’s share of opposite gender school friends negatively affects high school GPA. It uses the gender
composition of schoolmates in an individual’s neighborhood as
an instrument for the gender composition of an individual’s selfreported
friendship network. The effect occurs across all subjects
for students older than 16, but only in mathematics and science for
younger students. Additional results indicate effects may operate
inside the classroom through difficulties getting along with the
teacher and paying attention, and outside the classroom through
Paper: The Girl Next Door: The Effect of Opposite Gender Friends on High School Achievement, by Andrew Hill. Published in American Economic Journal: Applied Economics 2015, 7(3): 147–177.
A few personal comments:
I do not believe in single-mission education; I would not want to attend a school that only aims to maximize the test scores of their students.
A little bit of distraction can even promote creativity.
Slightly lower grades are probably a price worth paying if the student gains more and different friendships and is exposed to more diverse points of views or personalities.
That said, in those schools where very little learning is happening, improving the transmission of basic skills must be the priority. We should pay a lot more attention to the classroom environment especially in the schools and areas where students are stuggling.