Traffic collision

People assessing their odds of being involved in a car crash tend to dismiss evidence indicating that their risk is higher than they thought. Credit: Hair Fashion/Getty

Neuroscience

Stress opens the mind to bad news

When under threat, the brain takes both the good and the bad into account.

Cognitive science shows that people give more weight to positive information than negative information when forming beliefs about themselves — but new findings suggest that this bias seems to disappear when people are under threat.

Neil Garrett and Tali Sharot at University College London and their colleagues asked volunteers to consider 40 adverse events, such as a car accident, and to estimate their personal probability of experiencing each one. Then, for each event, the researchers delivered the ‘good’ or ‘bad’ news that the true risk was lower or higher than participants’ estimates. When asked to evaluate the adverse events again, volunteers tended to reduce their estimates of their own risk in response to good news, but often discounted bad news.

However, this pattern did not hold for a subset of participants who had been told at the study’s outset that they would have to give a public speech at the end of the experiment. Participants in this high-stress group gave good and bad news equal weighting in their updated risk assessments.