Kevin Drum is looking for a “Human Nature Top Ten” — well-established but underappreciated aspects of human psychology that illuminate behavior. His opening gambits are loss aversion and regression to the mean. I’d add adaptation effects, e.g. the hedonic treadmill: people adapt to changes in levels of (many) goods so that over time the additional good adds nothing to their levels of satisfaction. However, people tend to underestimate the strength of these effects on themselves and others. (E.g. Midwestern college students think that West Coast college students are happier because the weather is nicer; people think they’d be miserable in prison or in a wheelchair.)

Other candidates?