Book review: Liars and Outliers

During the 2003 London march to protest the beginning of the Iraq war, we shuffled very, very slowly over a clogged Waterloo Bridge. Monitoring helicopters waggled overhead. I marvelled at living in a society where 2 million people could protest under the eye of police without fear — that the government went on to ignore those 2 million protesters is a different issue.

That is a demonstration of trust, the subject of Bruce Schneier's latest book, Liars and Outliers: Enabling the Trust that Society Needs to Thrive. Schneier is well known for his security books such as Applied Cryptography and Secrets and Lies. But, as he argues at the beginning of Liars and Outliers, if you do not understand how trust works you cannot make good decisions about security.



To study trust, Schneier begins with evolutionary biology: the way plants and, later, animals evolved to protect themselves against predators. Those mechanisms worked fine for single organisms, but the big thing humans have is the ability to form societies and cooperate. Our problem today is that as biological organisms we evolved to instinctively understand relatively small groups — 150 is a common maximum. Schneier draws on the fields of sociology, evolutionary psychology, game theory, law, behavioural economics and many others to study the methods we have devised to replace what was once a simple matter of knowing each other.

The key element: how much cooperation is the right amount? If everyone cooperates, society stagnates and becomes a police state. If too many defect — an all-purpose term for moving in a direction against the norm, whether that be by committing a crime or blowing the whistle on corporate malfeasance — society becomes chaotic, lawless and dangerous. But, as Schneier goes on to argue through explorations of research and familiar thought experiments such as the Tragedy of the Commons and the Prisoner's Dilemma, the choice of whether to defect or cooperate is rarely straightforward. As societies get bigger and more complex, it requires the balancing of competing individual and group interests. On that day in 2003, the marchers were defectors from society at large. Yet they also formed a group with its own norms; the few protesters who caused trouble were defectors from that group. The whistleblower at Enron was a defector from her corporation — but she cooperated with the goals of society at large. And so on. How do we scale up trust to today's global level?

As you've probably guessed, this book is something of a departure from Schneier's previous work, which has been much more aimed at practical security. This book will not teach you how to secure a network or design an access control system for a major corporation. But that's not Schneier's purpose: he is trying to elucidate a framework for understanding our common problems. Technology provides new systems for validating trust, but also enables a smaller number of defectors to do more damage with greater reach. Yet, as noted, we can't afford, either economically or socially, to eliminate all defectors.

"Being alive entails risk," he writes, "and there will always be outliers."

Yet he ends on a note of optimism: we get these things mostly right. We hope anyone currently in their second hour of waiting on an airport security queue agrees.

Liars and Outliers: Enabling the Trust that Society Needs to Thrive
By Bruce Schneier
Wiley
365pp
ISBN: 978-1-118-14330-8
£21.99


Wendy M Grossman