Bruce Schneier is arguably the most well known cryptographer alive today, and for the past few years he's been doing fascinating research in the psychological factors surrounding risk and security.   A lot of this is related to airline security in particular, and the so-called "War on Terror " in various Western nations.   This latest article, "The War on the Unexpected ", makes fascinating reading:

http://www.schneier.com/blog/archives/2007/11/the_war_on_the.html

Also worth perusing, as a background, is "The Psychology of Security ":

http://www.schneier.com/essay-155.html

All of this might sound incredibly dry and boring, but few people appreciate just how   their decision making is underpinned by risk and reward judgments.   Worse, even fewer appreciate just how badly they bias these judgments with illogical and emotive reasoning.  

For example, I occasionally find myself chatting to people on aircraft.   I remember sitting next to one very nervous guy, who admitted that he'd was terrified of flying.

So let's look at a couple of uncomfortable statistics.   Your lifetime chance of dying in a car accident in the US is 1 in 84.   For an air and space transport accident it's 1 in 5,051.   That's on a per lifetime basis.   On a per trip basis the figures vary, but your chance of dying in a car accident is estimated to be ten times higher per trip than an ride in a commercial airliner.

So the car rides to and from the airport are the riskiest part of the journey!   Yet most people aren't terrified of the car trip.

So I explained this to the guy, which didn't help him much, but I could barely avoid laughing out loud when he told me what he'd been doing on holidays.   He'd been scuba diving, one of the riskiest sports.   To be afraid of flying but go scuba diving is insanely illogical.

But most people would agree with this person.   Why?   Because he had the illusion of control, or a "control bias " as Schneier calls it, which led him to underestimate the risks of scuba diving but be terrified on a commercial airliner.

For the morbidly inclined, here are the actual chance of death stats from the US National Safety Council:

http://www.nsc.org/lrs/statinfo/odds.htm

Other Western countries would be comparable.   There's a very nice chart here too:

http://www.nsc.org/lrs/statinfo/odds_dying.jpg

(Please don't be like one of my colleagues, who in a "blond " moment, asked why "Total odds of dying, any cause " was 1 in 1.)  

And for nervous fliers, some airline accident stats, of dubious value:

http://www.planecrashinfo.com/rates.htm