So you edited you message afterwards :<p>&gt; Equally decisive in determining crime rates are the more invisible barriers to crime set up by social norms and social cohesion. Indeed, one of the most robust statistical patterns known is that crime rates tend to go up with rising economic inequality, which itself tends to go along with erosion of social trust.<p>Well it doesn&#x27;t explain terrorism at all and that&#x27;s was the point your were trying to make. I&#x27;ll tell you what explains terrorism.<p>It&#x27;s growing in environment like some suburbs in France where you hear, from kindergarten to high-school , that &quot;white french are bad, white french girls are wh-res, and it&#x27;s fair game to kill non muslims&quot; , that&#x27;s the explanation as to why these people did what they did on friday. There is absolutely no other explanation. How do I know that? because I grew up in this kind of place.<p>You take the Roma, the Roma in France have it much much worse than any arab or black person ,victim a wide spread racism, living in slums where there is no electricity , no healthy water , among trash. Well now, give me an example of Roma terrorism in France.