The brain looks at the bright side of things

Scientists find good news changes people’s predictions more than bad news

From love and health to money matters, studies show that people tend to look on the bright side of many situations. Even when the reality is fairly grim, we think things will get better.

Scientists, of course, want to know why.

A new study finds that the human brain latches on to good news and disregards the bad. The scientists who conducted the study also identified parts of the brain that become active when a person receives good or bad news. The new research may show how thought processes guide human behavior.

“This is an excellent paper,” Read Montague told Science News. Montague, who was not involved in the new study, is a neuroscientist, someone who studies the brain and nervous system, at Virginia Tech in Blacksburg.

A recent study found that when making predictions, people tend to cling to good news and ignore the bad. istockphoto
The researchers enlisted the help of 19 volunteers. Each recruit studied a list of up to 80 negative things that can happen to a person. The list included having a car stolen, being diagnosed with a deadly disease, missing a flight, having fleas or lice and having a limb amputated. Each participant guessed his or her risk of going through each event. For example, a person might predict that he or she had a 40 percent chance of being diagnosed with cancer.

No one knows what will happen in the future. But we can make estimates. Risk, or probability, measures the likelihood that something will happen. The higher the probability, the higher the likelihood. When you go to class, there’s a high probability you’ll see your friend who sits next to you, but a low probability he’ll give you $100 (unless he owes you money).

In the experiment, each person first guessed his or her own risk of experiencing the negative events. Then, the researchers gave the participants their actual risk for each event. With that new information in mind, the participants reassessed their own personal risks. They were free to change their minds and their predictions.

If the new information brought bad news — for example, a woman learned she had a higher risk of cancer than originally guessed — she changed her initial guess by only a little. But if the new information brought good news — the woman faced a lower cancer risk — she changed her personal risk estimate by a lot. 

These results suggest that good news has a bigger impact than bad news on changing a person’s mind.

The participants estimated risks while undergoing a type of brain scan known as functional magnetic resonance imaging, or fMRI. Brain researchers employ fMRI to understand which parts of the brain perform tasks related to thinking. Here, scientists used fMRI to see which parts of the brain were more active when a person was considering good or bad news.

Unrealistic optimism can sometimes prove harmful. For instance, people who believe they have a low risk of health problems may decide not to buy health insurance. Or those who don’t worry about crime may not lock their doors.

On the other hand, ignoring bad news may be a good thing, University College London neuroscientist Tali Sharot, who worked on the new study, told Science News. Studies suggest that a positive outlook may lead to better health and longer life.

“It’s actually better for us,” she said.

Stephen Ornes lives in Nashville, Tenn., and his family has two rabbits, six chickens and a cat. He has written for Science News Explores since 2008 on topics including lightning, feral pigs, big bubbles and space junk.

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