This identification of a distinctive group of aggrieved young men emerged from the Youth Matters survey, carried out for the O2 telecommunications company, and analysed by Prof Chapman, who has researched young people and social mobility.

BBC: 'Angry young men' lack optimism

The fact that some of the attackers in Algeria were carrying Western identification -- two of them were reportedly Canadian -- will raise concern that the group could retask such recruits to launch attacks in the West.

CNN: Algeria attack changes terror landscape in North Africa