This is a hugely interesting subject, particularly given that the girls dressed as boys were in Afghanistan, where the segregation between men and women is so extreme. How then, is it possible for girls to pretend to be boys for many years, enjoying the same freedoms that boys enjoy? How is it that people who know the families and the children involved, just go along with the charade until the parents deem that the time is right for the girl to reappear?
The reasons for this pretense are varied. In poorer communities it could be that the family has no male member to operate outside the house; no-one to shop, or escort the daughters if they need to go out. Sometimes it is due to the belief that once a male child is born, others will follow, so a female child is dressed as a boy to help this 'magic' along. In one instance in the book, the child is a daughter of a female politician who has only daughters and who is more respected now that she has a 'boy'.
Then there is the question of how the girls are affected, both in the short term and longer. Having experienced the freedoms of being a boy and running unchecked through the streets, how difficult must it be to suddenly revert to being a demure young girl who looks no-one in the eye and rarely speaks? Mostly this change occurs around or before puberty, but sometimes it can go on into adulthood.
This book answers many of these questions and raises many more, but it did struggle to hold my interest, as it was a bit dry and long-winded, particularly towards the end where the author discusses the concept in the context of other cultures and periods of history and it started to feel more like a thesis.
For readers interested in the subject presented in a novel, I suggest The Pearl that Broke Its Shell by Nadia Hashimi (3.5 stars from me).