Hate can't be washed down with a few pints

How is it that people can be altruistic and also behave with abominable cruelty? Robin Dunbar considers the power of vendetta and paranoia in febrile minds

Ervin Staub's career has focused on genocide and group violence, which might be seen as the playing-out of his early childhood experiences. Like so many caught up in the Holocaust, he has spent much of his life trying to understand "man's inhumanity to man". He is the son of petit bourgeois Jewish parents in Budapest, and was six in the summer of 1944 when the Hungarian Nazi government rounded up its Jewish population and shipped it off to Auschwitz. Partly thanks to the legendary Raoul Wallenberg and his safehouse scheme, and partly through plain good luck, the entire family survived the vicissitudes of wartime Hungary and the forced labour camps, and managed to rebuild its business after the war - only to have it confiscated by the new Communist government. He was almost the last of his family to leave Hungary and he finally slipped across the border into Germany in the aftermath of the 1956 uprising. Eventually he made it to the US, where he graduated in psychology from Stanford University and stepped quickly into a job as an assistant professor at Harvard University.

Staub has spent the past four decades at the forefront of work on group violence, and this book is, in essence, an overview of his career.

It is a collection of his publications, edited and extracted to develop a theme through his life and work. It includes autobiographical sketches, short newspaper pieces, articles from academic journals and extracts from his books, dating from the early 1970s through to 2001 (a piece written in response to the events of September 11 2001).

Staub grapples with a lifelong puzzle: how can it be that people can be helpful and altruistic on some occasions and yet behave with such abominable cruelty on others? How was it, for example, that the Hutus in Rwanda could brutally set about exterminating the Tutsis, yet on other occasions engage in genuine acts of altruism by shielding and protecting potential victims - in some cases, murderer one day and protector against other murderers the next?

For Staub, there are two related issues here: how can we explain genocide and group violence (and hence be in a position to anticipate it)? And how can we prevent it?

To the first question, Staub's answer involves the familiar round of culprits. He says that groups that have suffered economic impoverishment and loss of dignity, those that have inherited a sense of grievance against more powerful neighbours, and those that are prone to scapegoating and have a cultural environment favouring authoritarian child-rearing practices and hostility towards outsiders are likely, sooner or later, to take their frustrations out on someone else. That someone can as easily belong to a class within society (intellectuals in Pol Pot's Cambodia) as to another racial group (Jews in 1930s Germany, blacks in early 20th-century America, Albanians in Kosovo).

For Staub, the archetypal population at risk of acting in this way was the body of German veterans in the aftermath of the first world war: disillusioned, defeated, their suffering in the trenches unappreciated by those back home, returning from battle to economic collapse and grinding poverty, they were, Staub argues, obvious prey for Nazi propaganda that promised a simple remedy for their problems.

In the end, however, neither Staub nor, so far as I know, anyone else has a genuinely satisfactory answer to this troubling aspect of human behaviour.

I suspect this is because they tend to focus closely on the social and economic aspects of the more spectacular examples. Staub alludes in passing to the long history of research on in-group/out-group phenomena in social psychology, and briefly to evolutionary perspectives on these processes, but he does not really get to grips with the lessons of history or with what evolutionary psychology has to offer.

One of the lessons of history, surely, is that many (though certainly by no means all) of these instances of genocide have the hallmarks of long-running vendettas. The Hutu-Tutsi conflict and events in the Balkans and Northern Ireland have long histories, in which first one side savages the other and then old scores are settled, decades - sometimes even centuries - later when the political tables are turned.

Individuals can bear grudges for a long time. So long as those grudges remain personal, they remain contained. It is when they are taken up as the folk wisdom of a community that they can get out of hand. Yet even then, they must begin with the paranoid views of one especially febrile individual. I cannot help feeling that it is our willingness to blame others for our misfortunes - a phenomenon amply exhibited in our now increasingly litigious society, fuelled by greedy lawyers and mediocre journalists desperate for public exposure - that lies at the root of the problem. Were we more willing to take responsibility for digging ourselves out of our holes, we might have fewer problems. However, blaming the neighbours is always an easy option.

If Staub himself is uncertain of the real answer to his first question, he is convinced that he knows the answer to the second. We can, he believes, prevent group violence breaking out by engaging in two simple strategies.

One is reconciliation. Staub has been instrumental in promoting a form of post-trauma counselling, having had projects running in Rwanda and elsewhere in which members of the victimised community talk face to face with members of the persecuting community. Socialising is a great leveller and there is nothing quite like an evening drinking together to breed a sense of genuine community. But Staub's interventions here seem to be more the kind of focus group favoured by slimmers' clubs or prison group confessional sessions. I do not know whether this kind of engagement ever breeds real understanding and empathy, and I see no evidence that it does in this volume. It is the loss of social capital that is the issue here, and that requires more than just a handful of reconciliation groups.

The other solution, Staub argues, is to encourage active bystanding. Staub is committed to the idea that group violence - whether it involves nationalist or racist groups or the police - can be controlled if bystanders are less passive. He argues that events evolve into open violence because passive bystanders fail to show disapproval. If other policemen had intervened in the Rodney King beating, he argues, the Los Angeles riots that summer would never have happened. If, instead of turning a blind eye, the United Nations and the US had intervened in Rwanda when warned by peacekeepers on the ground that something serious was brewing, then the Hutus would not have launched their murderous vendetta against the Tutsis in 1994. Staub's commitment to this idea has involved him in a number of programmes (including one with the US police) designed to encourage what he calls active bystanding.

I remain sceptical. Of course, intervention by bystanders works, but bystanders will become involved only if they believe that natural justice is somehow being infringed. And that presupposes that there are such things as natural rights that everyone accepts. And that flies in the face of the fact that rights are something we decide to accord each other. I doubt that even religious conviction would fill the gap, since religion has an unpleasant habit of generating rifts between believers and non-believers.

The reality is that most of the situations he is talking about are not those in which comic-strip rugby tackles of fleeing villains save the day: they are ugly and dangerous, and those who try to intervene are as likely as not to come off as badly as the victims.

In the end, I am not sure I learnt a great deal from this excessively long book. This was, first, because as a halfway house between a collected works and an attempt to promote a new idea it falls sadly between two stools.

And, second, because the endless repetition, in which the same few points are made about the same handful of events in a series of often-superficial analyses, seriously detracts from any real value it might have. The result is a book that lacks coherence, lacks any kind of thematic development and fails to offer a detailed, sophisticated analysis of a hugely important human problem. This is a lazy man's attempt to write a book - or a desperate editor's attempt to solicit a book from a well-known figure.

Robin Dunbar is professor of evolutionary psychology, Liverpool University.