What's the history of incest and cousin-marriage in Southern Asia and the Islamic World? Given the disabilities that result from such practices, have people always been aware of the risks? Is this a more recent phenomenon? | AskHistorians Archive Observer

What's the history of incest and cousin-marriage in Southern Asia and the Islamic World? Given the disabilities that result from such practices, have people always been aware of the risks? Is this a more recent phenomenon?

by 10z20Luka

This question is largely spurred by a recent documentary I saw on cousin marriage among Pakistani communities in the UK, for context. But I'm specifically looking for the historical understanding; if cousin marriage has been ongoing for centuries, wouldn't such diseases have been incredibly common?

Dinocrocodile

This answer focuses on Roman Egypt but /u/cleopatra_philopater answered In societies where incestual marriage with very close degrees of relation was tolerated/celebrated (eg; brother-sister pairings in Egypt) did people ever notice or point out that the children of such pairings seemed to die more often than ones produced from non-incestual marriages? and talked about the medical reasons for why such a practice might continue.