Bruce Schneier has an excellent essay up on his “Schneier on Security” blog, about the instinctive responses to threats of different species (including ours). He points out that these responses have typically evolved to balance the trade-off between the cost of reacting and the risk of not reacting when reaction is necessary. Birds (to use his example) will fly away from a bird feeder (free food) at the slightest possible threat. This may seem to be over-reaction, but the cost of flying away is probably quite small compared to the risk of being eaten, at least in the kind of environment in which the birds evolved.
Evolution generally does quite a good job of optimizing these trade-offs, but it doesn’t do a quick job. So, when the environment changes, old behavior patterns persist even though they are no longer really adaptive. Birds at a suburban backyard feeder or in a zoo aviary exhibit the same kind of reactions.
People are, or at least can be, different, since we have the capacity to use our reasoning abilities to override our “wired-in” evolutionary response. As he has argued many times (notably in his excellent book, Beyond Fear), Schneier thinks we need to practice this much more than we do.
Our reflexive defenses might be optimized for the risks endemic to living in small family groups in the East African highlands in 100,000 BC, not 2009 New York City.
When we rely mainly or solely on our instincts, we tend to do systematically dumb things. We conflate a feeling of control with a reduction in risk: driving a car is statistically much more dangerous than traveling on a commercial airline, but most peoples’ instincts have it the other way around. We tend to over-react to rare but spectacular risks. But it is possible to be sensible:
One night last month, I was awoken from my hotel-room sleep by a loud, piercing alarm. There was no way I could ignore it, but I weighed the risks and did what any reasonable person would do under the circumstances: I stayed in bed and waited for the alarm to be turned off.
False alarms are much more common than serious hotel fires.
Adopting this approach is not easy — it is by definition counter-intuitive — but it can help keep us safer in two ways: it will allow us to make more sensible decisions in everyday situations, like the hotel alarm; and it will help immunize us against people who attempt to push our “fear buttons” in order to advance their own agendas.