From the Europe of the Middle Ages to the wired world of today, The Why Factor this week looks at chastity – a complicated subject, tangled up with morality and modesty, with politics and religion, and with the role of women through the ages. Mike Williams speaks to, among others, an American campaigning for abstinence in US schools and a nun for whom chastity is an important part of the job. He examines chastity chosen, and chastity imposed.

Produced by Nina Robinson

Picture: Chastity belt, Credit: BBC