Choosing What Makes Us Happy (5): Memory Bias

People draw on their memories of past events to forecast their reactions to future events. However, this process has been shown to introduce biases into evaluations. Memory based evaluations are influenced by the peak-and-end rule. This rule states that people’s global evaluations of previous events can be predicted by the affect experienced during just two moments: the moment of peak affect intensity and the ending. This sort of evaluation generally ignores the event’s duration and other related events.

Thus if people remember last year’s family outing by recalling its rare moments of thrill on the water-rides, then they may make predictions and plans accordingly, only to find themselves once again jostling in ticket and food queues at an overcrowded park.

There is also a common tendency to recall and rely on atypical instances. In studies, participants who were asked to recall a single instance of an event, or to recall no
event at all, made extreme forecasts about the future.

To counter memory bias it is suggested that one should recall more than one past event of that type and also focus on the whole event.