Optimism is typically defined as a tendency to have positive expectations about the future. And even though researchers have been studying this cheery trait for decades, its neurobiological basis has largely remained a mystery.
And this is a major gap, because optimism plays an important role in people’s physical and psychological health. For example, previous research has shown that optimistic people have longer life spans and handle stress better.
They also perform better at work, have broader social networks, and experience greater overall life satisfaction.
Likewise, less optimistic people experience more loneliness, higher risks of psychiatric disorders, and slower recovery rates after surgery.
Locating optimism in the brain
And that’s why identifying the links between optimism and the brain will help create more positive health outcomes. With this in mind, researchers in China and Hong Kong recently conducted a study to map out these connections.
Their study involved giving MRI scans to 231 Chinese adolescents aged between 16 and 20. The participants were about evenly split between men and women. To measure their optimism, the subjects filled in a questionnaire called the Revised Life Orientation Test (LOT-R). It asks subjects to indicate how strongly they agree with statements such as “In uncertain times, I usually expect the best.”
Results: the key role of the putamen
Their analysis showed a significant positive correlation (r = .69) between optimism and the density of the putamen. This is a round structure located at the front of the brain.
There were no associations between optimism and the other measured qualities. These included age, IQ, socioeconomic status, sex, or any of the Big 5 personality traits except for extroversion.
The strong association with extroversion (r = .31), was expected. Indeed, much previous evidence has show that extroversion is an important factor in optimism. The researchers also found that extroversion accounted for most (but not all) of the association with putamen density.
This finding fits well with previous results showing that a diminished putamen structure is common in psychiatric disorders related to low optimism, such as depression, anxiety, and post-traumatic stress disorder.
Likewise, other studies have shown that the putamen plays a key role in anticipating rewards, and taking action to get those rewards. This may be because people with greater putamen density consider future events to be more rewarding based on their past experience.
Interventions to promote optimism
This is the first study to look specifically at optimism’s links to brain structure in adolescents. Researchers are increasingly recognizing the role that optimism plays in adolescent health (such as a lower risk of physical and mental disease) as well as developmental outcomes (like higher subjective well-being).
This research will help scientists design interventions aimed at improving optimism levels, especially among adolescents. Increasing optimism, so goes the thinking, will help increase adolescents’ quality of life, and minimize the health risks associated with low optimism.
The study is also an important contribution to the growing field of psychoradiology, which explores abnormal brain changes in psychiatric disorders, and offers help in deciding how to treat those disorders.
Study: “Neurostructural correlates of optimism: Gray matter density in the putamen predicts dispositional optimism in late adolescence” (doi.org/10.1002/hbm.24888)
Authors: Han Lai, Song Wang, Yajun Zhao, Chen Qiu, Qiyong Gong
Published in: Human Brain Mapping, December 2019
Photo: by Andrea Piacquadio from Pexels
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