A potential mechanism by which levels of optimism are adapted to the relative safety or danger of the environment has been designed by scientists and published in JNeurosci.
In general people tend to be overly optimistic. The opposite is true in psychiatric conditions such as depression, in which some patients place a premium on negative information. Neil Garrett, Tali Sharot, and colleagues now show that the ability to flexibly shift between these two patterns can be a healthy, adaptive response to changing environmental demands.
‘Laboratory and natural experiments demonstrate how threat dissolves human optimism bias.’
The researchers induced stress in a controlled laboratory experiment by telling participants they will need to give a surprise public speech. They then asked participants to estimate their likelihood of experiencing 40 different aversive events in their life, such as being involved in a car accident or becoming a victim of card fraud. Participants were then given either good news (being told that their likelihood of experiencing these events was lower than they had estimated) or bad news (that it was higher). They then asked participants to provide new estimates. The control group showed the well-known optimism bias; a tendency to take more notice of good news compared to bad news. In contrast, the stressed participants showed no such bias and became better at processing bad news. The researchers obtained similar results in a study of Colorado firefighters, who naturally experience fluctuating periods of stress as part of their job.