Radicalization : why some people choose the path of violence

In the wake of the Paris, Beirut, and San Bernardino terrorist attacks, fears over 'homegrown terrorism' have surfaced to a degree not seen since September 11, 2001.

A sought-after commentator in France and a widely respected international scholar of radical Islam, Farhad Khosrokhavar has spent years studying the path towards radicalization, focusing particularly on the key role of prisons - based on interviews with dozens of Islamic radicals - as incubators of a particular brand of outrage that has yielded so many attacks over the past decade.