The Psychology of Security - Essay by Schneier

Security is both a feeling and a reality. And they're not the same.

The reality of security is mathematical, based on the probability of different risks and the effectiveness of different countermeasures. We can calculate how secure your home is from burglary, based on such factors as the crime rate in the neighborhood you live in and your door-locking habits. We can calculate how likely it is for you to be murdered, either on the streets by a stranger or in your home by a family member. Or how likely you are to be the victim of identity theft. Given a large enough set of statistics on criminal acts, it's not even hard; insurance companies do it all the time.

We can also calculate how much more secure a burglar alarm will make your home, or how well a credit freeze will protect you from identity theft. Again, given enough data, it's easy.

But security is also a feeling, based not on probabilities and mathematical calculations, but on your psychological reactions to both risks and countermeasures. You might feel terribly afraid of terrorism, or you might feel like it's not something worth worrying about. You might feel safer when you see people taking their shoes off at airport metal detectors, or you might not. You might feel that you're at high risk of burglary, medium risk of murder, and low risk of identity theft. And your neighbor, in the exact same situation, might feel that he's at high risk of identity theft, medium risk of burglary, and low risk of murder.

Or, more generally, you can be secure even though you don't feel secure. And you can feel secure even though you're not. The feeling and reality of security are certainly related to each other, but they're just as certainly not the same as each other. We'd probably be better off if we had two different words for them.

This essay is my initial attempt to explore the feeling of security: where it comes from, how it works, and why it diverges from the reality of security.

Four fields of research—two very closely related—can help illuminate this issue. The first is behavioral economics, sometimes called behavioral finance. Behavioral economics looks at human biases—emotional, social, and cognitive—and how they affect economic decisions. The second is the psychology of decision-making, which examines how we make decisions. Neither is directly related to security, but both look at the concept of risk: behavioral economics more in relation to economic risk, and the psychology of decision-making more generally in terms of security risks. But both fields go a long way to explain the divergence between the feeling and the reality of security and, more importantly, where that divergence comes from.

There is also direct research into the psychology of risk. Psychologists have studied risk perception, trying to figure out when we exaggerate risks and when they downplay them.

A forth relevant field of research is neuroscience. The psychology of security is intimately tied to how we think: both intellectually and emotionally. Over the millennia, our brains have developed complex mechanisms to deal with threats. Understanding how our brains work, and how they fail, is critical to understanding the feeling of security.

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