*You ever notice
how anyone driving slower than you is an idiot,
and anyone driving faster than you is a maniac?
-- George Carlin*

The expected values of A and B are the same, likewise C and D. So we might expect people in the first group to choose A 50% of the time and B 50% of the time, likewise C and D. But some people prefer "sure things", while others prefer to gamble. According to traditionalHere's an experiment .... Subjects were divided into two groups. One group was given the choice of these two alternatives:

- Alternative A: A sure gain of $500.
- Alternative B: A 50% chance of gaining $1,000.
The other group was given the choice of:

- Alternative C: A sure loss of $500.
- Alternative D: A 50% chance of losing $1,000.

This gave rise to something calledBut experimental results contradict this. When faced with a gain, most people (84%) chose Alternative A (the sure gain) of $500 over Alternative B (the risky gain). But when faced with a loss, most people (70%) chose Alternative D (the risky loss) over Alternative C (the sure loss).

As before, the expected values of A and B are the same, likewise C and D. But in this experiment A==C and B==D -- they are just worded differently. Yet human bias toward sure gains to and potential losses holds true, and we reach an incongruous result: People overwhelmingly prefer Program A and Program D in their respective choices! While Schneier looks at how these biases apply to the trade-offs we make in the world of security, I immediately began thinking of software development, and especially the so-called agile methods. First let's think about gains. If we think not in terms of dollars but in terms ofIn this experiment, subjects were asked to imagine a disease outbreak that is expected to kill 600 people, and then to choose between two alternative treatment programs. Then, the subjects were divided into two groups. One group was asked to choose between these two programs for the 600 people:

- Program A: "200 people will be saved."
- Program B: "There is a one-third probability that 600 people will be saved, and a two-thirds probability that no people will be saved."
The second group of subjects were asked to choose between these two programs:

- Program C: "400 people will die."
- Program D: "There is a one-third probability that nobody will die, and a two-thirds probability that 600 people will die."