When confronted with a decision, humans regularly make judgments based on recent events or information that can be easily recalled. This is known as the availability heuristic.
Says Kahneman, "The availability heuristic... substitutes one question for another: you wish to estimate... the frequency of an event, but you report the impression of ease with which instances come to mind."
Cable news provides plenty of fodder for this mental shortcut. For example, viewers of Entertainment Tonight probably think that celebrities divorce each other once every minute. The actual numbers are more complicated, and far less exorbitant.
It's important to be cognizant of the availability heuristic because it can lead to poor decisions. In the wake of the tragic events of 9/11, with horrific images of burning buildings and broken rubble fresh in their minds, politicians quickly voted to implement invasive policies to make us safer, such as domestic surveillance and more rigorous airport security. We've been dealing with, and griping about, the results of those actions ever since. Were they truly justified? Did we fall victim to the availability heuristic?