There's no profile:
MI5 has concluded that there is no easy way to identify those who become involved in terrorism in Britain, according to a classified internal research document on radicalisation seen by the Guardian.
[...]
The main findings include:
• The majority are British nationals and the remainder, with a few exceptions, are here legally. Around half were born in the UK, with others migrating here later in life. Some of these fled traumatic experiences and oppressive regimes and claimed UK asylum, but more came to Britain to study or for family or economic reasons and became radicalised many years after arriving.
• Far from being religious zealots, a large number of those involved in terrorism do not practise their faith regularly. Many lack religious literacy and could actually be regarded as religious novices. Very few have been brought up in strongly religious households, and there is a higher than average proportion of converts. Some are involved in drug-taking, drinking alcohol and visiting prostitutes. MI5 says there is evidence that a well-established religious identity actually protects against violent radicalisation.
• The "mad and bad" theory to explain why people turn to terrorism does not stand up, with no more evidence of mental illness or pathological personality traits found among British terrorists than is found in the general population.
• British-based terrorists are as ethnically diverse as the UK Muslim population, with individuals from Pakistani, Middle Eastern and Caucasian backgrounds. MI5 says assumptions cannot be made about suspects based on skin colour, ethnic heritage or nationality.
• Most UK terrorists are male, but women also play an important role. Sometimes they are aware of their husbands', brothers' or sons' activities, but do not object or try to stop them.
• While the majority are in their early to mid-20s when they become radicalised, a small but not insignificant minority first become involved in violent extremism at over the age of 30.
• Far from being lone individuals with no ties, the majority of those over 30 have steady relationships, and most have children. MI5 says this challenges the idea that terrorists are young men driven by sexual frustration and lured to "martyrdom" by the promise of beautiful virgins waiting for them in paradise. It is wrong to assume that someone with a wife and children is less likely to commit acts of terrorism.
• Those involved in British terrorism are not unintelligent or gullible, and nor are they more likely to be well-educated; their educational achievement ranges from total lack of qualifications to degree-level education. However, they are almost all employed in low-grade jobs.
