In recent decades arguments for and against single-sex education have heated up. Many parents realize that the choice between single-gender and coeducational schooling has important implications for the academic, psychological and social development of their kids. A few years ago, when I was looking at middle schools for my daughter, The Case Against Single-Sex Classrooms. By Margaret Talbot. July 11, The case for and against all-boys and all-girls schools. Places to Live; K; Colleges; Niche Blog the number of single-sex schools in the United States rose.