The brutalised boy soldiers in Liberia, racing around in trucks firing their Kalashnikovs, provided some of the most shocking pictures of the summer. The images are so appalling that it is difficult to think clearly about what lies behind them. But I believe they contain a crucial clue to the problem of violence and disorder, not just around the world but also closer to home.
The clue is there in front of us on the television-these are societies with crowds of youngsters and few adults. The boy soldiers of Liberia are living in an extraordinarily youthful society. In Liberia, the median age-the point at which there are equal numbers of people above and below-is only 16.6 years. By contrast, the median age in Britain is 20 years older-37.7.
The Centre for Strategic and International Studies in Washington has identified a clear pattern-the world's trouble spots are the states with the youngest populations. Of the world's 25 most youthful countries, 16 have experienced major civil conflict since 1995. And this is not a new phenomenon. China's median age at the time of the cultural revolution was 19. Iran's median age when the Shah was deposed was 17. What do Afghanistan, Iraq, Syria and Pakistan all have in common now? They all have a median age of under 19. In Palestine it is 17; in Yemen it is 15. These are teenage countries. Among countries with the oldest populations, only Croatia has been involved in conflict over the past 15 years. Japan, the world's oldest country with a median age of 41.3 years, is also one of the most pacific.
William Golding's famous novel Lord of the Flies is a terrible picture of children turning feral when they find themselves trapped on an island without an adult after a plane crash. The television images from Liberia, or the Democratic Republic of Congo (median age 16.5 years) or Sierra Leone (median age 17.9 years) are horrific re-enactments of that novel.
But this is all going to change over the next 50 years as the world grows older. The UN projects the world's median age will rise from 26.4 years now to 36.8 years in 2050. We should be heading for a less violent future. We might indeed face the opposite problem-being almost too stable and conformist. That is the situation much of Europe faces already.
Indeed, in Europe we are ageing so fast that this analysis of youthful and disorderly societies may seem far removed from our concerns. Yet it helps to explain our own social problems too. We are all familiar with the interaction of family breakdown, drugs, crime, unemployment and welfare dependency that blights the most deprived communities. But there is one factor which almost all commentators ignore. Our most deprived communities are much younger than the rest of the country.
We have about 12m children in a population of almost 60m. On average, therefore, across the country there is approximately one child to four adults. But children and adults are not spread in even ratios everywhere. Some communities have much higher rates of children to adults. Some of our social housing projects have ended up with three children to every two adults.
I was recently in Aston, Birmingham, talking to young black people who are trying to reverse the spread of gun culture. This analysis struck a chord with them. Their community has large numbers of young people with relatively small numbers of older adults to maintain order.
Child density has long been recognised as an important element in protecting estates from the antisocial behaviour, vandalism, graffiti and drugs that drag them down. Back in the 1970s the official guidance for new housing projects was that there should be three adults to every child. But successive governments have failed to ensure a good age mix. Welfare and housing rules understandably give priority to families with children. The result is that many estates are filled with families with young children-some of them lone-parent families-storing up problems for later when the teenagers come to outnumber the adults.
There is another twist to this which, in a way, gives us some hope. Communities don't suffer steady social decline as child density rises. There appears to be a clear tipping point after which they deteriorate dramatically. We need to make sure we don't push our most vulnerable communities over that tipping point.
Sometimes you hear people say that a part of their town is as bad as Beirut or Baghdad. Those comments contain a kernel of truth. The world's most troubled countries are wrestling with the social consequences of dramatic demographic change: they can't handle youthfulness. Meanwhile, we have managed to replicate the conditions of these youthful and disorderly societies in our own middle-aged country. This is not a "natural" phenomenon-it is the product of the housing and welfare policies of successive governments. It is up to governments to correct it too.
