I mentioned on a previous blog post the idea that the proportion of young men in a population may help determine the extent of violence and instability in it.
Just noticed an astonishing population pyramid, comparing the average ages of the Irish population as a whole with the average ages of Ireland's Traveller Community. There is a stark difference between the two. With high mortality rates and high fertility rates, the Travellers have a far higher proportion of children than Irish as a whole.
In Ireland there is a slightly higher number of people from 40-44 years of age than people from 0-4 years of age. For Travellers, there are well over three times as many 0-4 year old infants than adults of 40-44. I wonder if this Youth Bulge may play a role in shaping the perceived behaviour of Travellers? If they have fewer gentle old folk compared with a large, impulsive young population, the "average" Traveller may be more likely to be involved in crime, simply because he is more likely to belong to the age group that tends to dabble in it - in every culture.