There is a social psychologist at Harvard University by the name of Dan Gilbert. Gilbert's best-selling book, Stumbling on Happiness, discusses the many ways in which we miscalculate how situations will make us happy or sad, and reveals some counterintuitive insights about how to be happy.
When we think about some emotional event, we tend to over-estimate how strongly we will feel, how long this will last and other factors that impact us. This applies to both negative and positive events.
In doing so, we tend to forget that other events in our life, as well as our general ability to recover from trauma will mitigate these feelings. Gilbert et al called this ability to recover the 'psychological immune system', in the way that we psychologically fight bad feelings and hence recover from trauma faster than we might otherwise do.
One of the primary discoveries from researchers like Gilbert is that extreme inescapable situations often trigger a response from our brain that increases positivity and happiness.
For example, imagine your house is destroyed in an earthquake or you suffer a serious injury in a car accident and lose the use of your legs. When asked to describe the impact of such an event most people talk about how devastating it would be. Some people even say they would rather be dead than never be able to walk again.
But what researchers find is that when people actually suffer a traumatic event like living through an earthquake or becoming a paraplegic their happiness levels are nearly identical six months after the event as they were the day before the event.
How can this be?
Traumatic events tend to trigger what Gilbert refers to as our “psychological immune systems.” Our psychological immune systems promote our brain’s ability to deliver a positive outlook and happiness from an inescapable situation. This is the opposite of what we would expect when we imagine such an event. As Gilbert says, “People are not aware of the fact that their defenses are more likely to be triggered by intense rather than mild suffering. Thus, they mispredict their own emotional reactions to misfortunes of different sizes.”
This effect works in a similar way for extremely positive events. For example, consider how it would feel to win the lottery. Many people assume that winning the lottery would immediately deliver long-lasting happiness, but research has found the opposite.
In a very famous study published by researchers at Northwestern University in 1978 it was discovered that the happiness levels of paraplegics and lottery winners were essentially the same within a year after the event occurred. You read that correctly. One person won a life-changing sum of money and another person lost the use of their limbs and within one year the two people were equally happy.
It is important to note this particular study has not been replicated in the years since it came out, but the general trend has been supported again and again. We have a strong tendency to overestimate the impact that extreme events will have on our lives. Extreme positive and extreme negative events don’t actually influence our long-term levels of happiness nearly as much as we think they would.
The Impact Bias is one example of affective forecasting, which is a social psychology phenomenon that refers to our generally terrible ability as humans to predict our future emotional states.