Kevin Drum in Mother Jones posits this idea:
There are several fascinating components to prospect theory, but the one that’s influenced me the most is also the simplest: when faced with a choice, people are far more motivated by loss aversion than by risk aversion.
Basically, what this means is that the emotional distress you suffer from losing, say, $100, is much greater than the emotional lift you get from winning $100. Losses always loom larger than gains.
The power of loss aversion is one of those insights that seems painfully obvious after someone else points it out, and once you start looking for it you can see it in all walks of life. People are simply not willing to risk losing something they already have unless they’re promised a credible chance of a much larger gain. This explains a lot of otherwise odd behaviors…